Sociological Methods & Research
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Studying Rare Events Through Qualitative Case Studies: Lessons from a Study of Rampage School
Shootings
DAVID J. HARDING, CYBELLE FOX and JAL D. MEHTA
Sociological Methods Research 2002; 31; 174
DOI: 10.1177/0049124102031002003
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This article considers five methodological challenges in studying rare events such as
school shootings. Drawing on the literature on causal analysis in macro-historical
and other small-N research, it outlines strategies for studying school shootings using
qualitative case studies and illustrates these strategies using data from case studies of two
rampage school shootings: Heath High School in West Paducah, Kentucky, and Westside
Middle School outside Jonesboro, Arkansas. Strengths and limitations are discussed as
well as lessons for studying rare events.
Studying Rare Events Through
Qualitative Case Studies
Lessons From a Study of Rampage School Shootings
DAVID J. HARDING
CYBELLE FOX
JAL D. MEHTA
Harvard University
INTRODUCTION
Lethal violence in America’s schools is a rare event. According to
estimates by the Centers for Disease Control, the probability of a child
dying in school in any given year from homicide or suicide was less
than one in 1 million between 1992 and 1994 and slightly greater
than one in 2 million between 1994 and 1999 (Kachur et al. 1996;
Anderson et al. 2001). When one examines so-called rampage killings
AUTHORS’ NOTE: This research was funded by grants from the National Academy of
Sciences and the William T. Grant Foundation (Katherine Newman, principal investigator), by National Science Foundation Graduate Research Fellowships awarded to each
of the authors, and by a National Science Foundation Integrative Graduate Education
and Research Traineeship Grant (98070661). We thank Katherine Newman, Wendy
Roth, Christopher Winship, and an anonymous reviewer for helpful discussions and
comments. The authors can be contacted at the Department of Sociology, Harvard
University, 33 Kirkland St., Cambridge, MA 02138; e-mail [email protected],
[email protected], or [email protected].
SOCIOLOGICAL METHODS & RESEARCH, Vol. 31 No. 2, November 2002 174-217
DOI: 10.1177/004912402237293
© 2002 Sage Publications
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Harding et al. / STUDYING RARE EVENTS
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such as the massacre at Columbine High School on April 20, 1999 (or
attempts at such killings), the number of events drops to between 30
and 50 in the past three decades, depending on how one classifies such
events.
Despite their rarity, public concern over rampage school shootings has been high. Parents report fearing for their children’s safety
at school, and many students suspect an attack could occur at their
school.1 As exhibited by the myriad studies of school shootings by government and nonprofit agencies in the past half decade (e.g., O’Toole
2000; Anderson et al. 2001; Vossekuil, Reddy, and Fein 2000; National
School Safety Center 2001; Dunn and Frost 2000; State of Colorado
2001; National Research Council and Institute of Medicine 2002),
much of the concern derives from an inability to understand and
predict such tragedies. Rampage school shootings occur in seemingly otherwise safe schools and communities, rural and suburban
areas where students are predominantly White and working or middle
class, communities that have previously escaped the youth violence
associated with inner-city minority neighborhoods. The public has
understandably demanded insight on the causes of such events and
how to prevent them. The string of school shootings and the public
concern over them provide sociologists and other social scientists an
opportunity to inform public discourse and policy if only we can figure
out how to study such extremely rare events.
Social science methodologies traditionally used to study crime,
delinquency, education, and the like do not fare well in explaining
events as rare as rampage school shootings. Previous studies of rampage school shootings such as those conducted by the Federal Bureau
of Investigation (O’Toole 2000), the U.S. Secret Service (Vossekuil
et al. 2000), the Centers for Disease Control (Anderson et al. 2001),
and academics (McGee and DeBernardo 1999; Verlinden, Hersen, and
Thomas 2000; Meloy et al. 2001) have been quantitative in nature.
They rely on identifying a population of events, gathering information
on a sample of such events, and comparing and contrasting events to
determine commonalities and differences. Unfortunately, these methods make it difficult to gather data on causal factors at various levels
(micro, meso, macro) or to understand how various causal factors
interact to produce school shootings.
Of course, school shootings are not the only rare events of interest to
sociologists and other social scientists. Rare events may be of interest
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to social scientists because they are of great concern to the public,
involving great loss of life or great cost. Examples include hijackings (Holden 1986), nuclear accidents and other man-made disasters
(Perrow 1984), and accidents such as the Challenger space shuttle
explosion (Vaughan 1986, 1999). Rare events such as workplace shootings or other forms of mass murder (see Levin and Fox 1985; Fox and
Levin 1994, 1998) may also be of interest to the public because, like
school shootings, they create widespread fear. Other rare events are
of interest to social scientists because, as a rupture of the routine,
they shed light on social processes and social problems. Examples
include race riots (Bergesen and Herman 1998; Olzak, Shanahan,
and McEneaney 1996), mass suicide (Moore and McGehee 1989),
and victim-precipitated homicide or “suicide by cop” (Hutson et al.
1998; Poussaint and Alexander 2000). Still other rare events may be
of interest because of their inherent importance to the legitimacy of
basic social institutions. For example, political scientists and political sociologists have long been interested in coups (O’Kane 1981),
assassinations (Crotty 1998), and impeachments (Benedict 1998,
Popp 2000).
This article will explore the ways in which in-depth qualitative case
studies can contribute to the study of rare events by drawing on lessons
learned in our own research on two cases of rampage school shootings. It will discuss and illustrate strategies for understanding school
shootings, focusing not on the specifics of a formal method of data
gathering or data analysis but on the underlying logic or logics of using
detailed data from a single case or small number of cases to understand
necessary but not sufficient conditions for school shootings. We will
focus on both the benefits and limitations of the types of analyses we
describe and will comment on the potential for generalization beyond
individual cases from such analyses.
We begin by discussing five challenges in the study of school shootings and other rare events and draws on previous methodological
work on rare events and small-N analysis to develop strategies for
studying school shootings. The next section briefly summarizes our
research on two school shooting cases, the shootings at Westside
Middle School outside Jonesboro, Arkansas, and Heath High School
in West Paducah, Kentucky. Then we explore strategies for explaining
school shootings through qualitative case studies, illustrating the utility
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of such strategies by drawing on the two cases studied. The following
section discusses the strengths and limitations of our strategies as well
as avenues for future research. Finally, we conclude with lessons for
studying rare events.
CHALLENGES IN THE STUDY OF SCHOOL SHOOTINGS
THE CASE DEFINITION PROBLEM
One of the first problems we confront in studying school shootings is
defining the relevant universe of cases that can realistically be called
rampage school shootings. Consider the 1998 shooting in Fayetteville,
Tennessee. In a school parking lot, Jacob David, an 18-year-old honor
student, fatally shot a classmate who was dating his ex-girlfriend.
Given that this shooting involved only one victim with whom the
assailant had a personal grudge, does it qualify as a rampage school
shooting? Consider also the incident in Conyers, Georgia, on May 20,
1999, in which T. J. Solomon, 15, opened fire in the lobby of his high
school, injuring 6 students (Sullivan and Guerette 2002). Given that no
one died as a result of this attack, should it be considered in the same
group as the massacre at Columbine High School one month earlier?
Finally, consider the shooting at Thomas Jefferson High School in East
New York on November 21, 1991, in which Jason Bentley drew his
gun and fired two shots when he thought another student in a hallway
confrontation was reaching for a gun. One student was killed and one
teacher wounded (Fullilove et al. 2002). Given that the attacker felt he
was acting in self-defense, should it be compared to planned attacks?
What factors distinguish a rampage school shooting from other types
of shootings? The definition used to identify a positive case can have
a significant impact not only on our assessment of how rare the event
actually is but also on the substance of the theory that is subsequently
developed to explain the phenomenon. We call this the case definition
problem.
Determining what a case is has generally been undertheorized in
the social sciences (Ragin and Becker 1992). Classifying events as
school shootings often depends on the question that is being asked.
While some authors believe that one’s case and population of cases
should be determined at the outset of the research, others believe
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that determining what a particular event is a case of should be an
inductive or iterative process. This split, perhaps not surprisingly, often
follows the quantitative-qualitative or variable oriented–case oriented
methodological divides (Ragin 1997, 1998, 1999).According to Ragin,
Howard Becker, who falls squarely on the inductive side of this debate,
argued that
researchers probably will not know what their cases are until the
research, including the task of writing up the results, is virtually completed. What it is a case of will coalesce gradually, sometimes catalytically, and the final realization of the case’s nature may be the most
important part of the interaction between ideas and evidence. (Ragin
and Becker 1992:6)
It should come as no surprise, then, that there is no consistent definition of school shootings or population of events called school shootings
in what little empirical work exists. Some researchers have taken a very
broad approach while others have taken a narrow approach.2 One of the
advantages of taking a broad approach is a larger potential sample size.
One might treat rampage school shootings as a particular instance of
lethal school violence or perhaps even as an extreme manifestation of
nonlethal school violence. Another way of increasing the number
of cases that is sometimes used in comparative historical research is
shifting the unit of analysis so as to compare and contrast subunits
within a case (King, Keohane, and Verba 1994). The prototypical
example is increasing the number of cases by comparing and contrasting states rather than simply taking the United States as a single case.
However, one must be sure to have compelling theoretical reasons that
legitimate shifting the unit of analysis or treating one event as a more
extreme manifestation of another more common occurrence. Often in
case-oriented research, the cases are purposefully selected because of
their political or historical significance (Ragin 1997). We return to this
issue in the discussion section.
THE COMPARISON CASE PROBLEM
A second problem for studying school shootings related to our first is
identifying the relevant “nonevent” with which cases of the outcome
could be contrasted. If we limit ourselves to studying cases in which
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school shootings occur, we cannot determine which causes are sufficient to produce a school shooting. However, given that the cause(s)
may exist at different theoretical levels of analysis—individual, school,
community, and even nation—a wide variety of comparative nonevents
might seem appropriate. We might imagine comparing the shooter
with nonshooters at the same school or comparing a school where
a shooting occurred to another school in the same community, or
different communities in the same nation, or compare the United States
with a similar nation that has not had school shootings. That school
shootings are extremely rare events suggests that cases in which they
do occur may be somehow extreme on many causal variables, making
selection of comparison cases even more difficult. We call this the
comparison case problem.
Some reviewers of the literature on comparison cases have claimed
that an exclusive focus on positive cases, as we do here out of necessity,
results in the problems of “selection on the dependent variable” that
can plague both small and large N research (Geddes 1990).3 By this
logic, if cases are chosen on the basis of the dependent variable, one
sees only a truncated part of the distribution of the dependent variable,
and this can induce bias. However, as Dion (1998) pointed out most
recently, variation in the dependent variable is important only if one
seeks to assess sufficient conditions. Dion noted that factors that are
extremely unimportant from the perspective of sufficiency (perhaps
less than 1/100 of 1 percent of youth with access to guns commit school
shootings) can nonetheless be very important from the perspective
of necessary factors (100 percent of the school shootings involved
youth with access to firearms). From the perspective of identifying
necessary but not sufficient factors, negative cases do not provide
relevant information.
THE DEGREES OF FREEDOM PROBLEM
A third problem arises when there are a relatively small number of
cases as well as a large number of potential causes. For example, there
are only a handful of cases of rampage school shootings and almost
a dozen variables that have been proposed as likely causes, including
firearm availability, violent media, family breakdown, southern culture
of violence, bullying, and so forth. With so many possible causes and
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so few cases, it is difficult to isolate the effect of any one variable. This
problem is traditionally known as the degrees of freedom problem.
A promising line of work to handle the degrees of freedom problem can be found in Skocpol’s States and Social Revolutions (1979).
Skocpol made a strong case that this task can be taken on with the
help of Mill’s (1974) methods of agreement and difference.4 Using
Mill’s method of agreement, Skocpol argued that the combination
of a weak state and agrarian sociopolitical structures conducive to
peasant revolt are the common factors in three states that experienced
social revolutions (France, Russia, and China). Using Mill’s method
of difference, Skocpol claimed that this same combination of factors
was not present in five comparison cases that did not experience
revolutions (England, prerevolutionary Russia, Germany, Prussia, and
Japan) and that the comparison cases were similar to the states experiencing social revolutions on other factors that scholars had argued
precipitated revolutions. This allowed her to posit that this combination
of conditions was both necessary and sufficient for explaining social
revolutions. She ruled out causes proposed by other scholars, such as
relative deprivation and urban worker revolts, because they are present
but do not lead to the outcome in comparison cases. Thus, Skocpol
highlighted the attractive nature of Mill’s logic in small-N research; it
allows the researcher to evaluate different causal theories, even when
there are more theories than data points (Lipjhart 1971).
It is exactly this attractive feature of Mill’s (1974) methods that
has come under attack by researchers who posit that Mill’s method of
difference assumes a deterministic conception of causal social theories (Nichols 1986; Lieberson 1991, 1994; Goldstone 1997). The real
world is probabilistic, these scholars argue. Sometimes, events are
caused by unanticipated reasons or even random chance, and thus the
enterprise of trying to place every data point into a causal theory is not
realistic. Worse, the attempt to fit every instance (in large-N language
to “account for all the variation”) after looking at the data amounts
to data dredging and can produce distorted theories (Lieberson 1991).
In reply, Skocpol (1986; Skocpol and Somers 1980) has defended
a conception of research that works iteratively between induction
and deduction in an effort to avoid armchair theorizing and find a
theory that accurately reflects the data. Ragin (1997, 1998) argued
that case-oriented research is not inherently deterministic but rather
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that determinism must be specifically theorized and that determinism
and goodness of fit are separate issues. The debate over whether a
single case study that disconfirms a prominent thesis is important for
theory building splits along similar lines, with some suggesting that
attempting to account for anomalies is central to the practice of theory
building (Eckstein 1975; George 1979; Kuhn 1962) and others arguing
that in a probabilistic world, a single disconfirming case study may not
be evidence of anything more than chance or measurement error (King
et al. 1994).
Bypassing this debate over the merits of Mill’s (1974) methods,
Mahoney (1999, 2000) provided three alternative strategies that can
be used by small-N researchers (and are implicitly used by Skocpol)
as they attempt to weigh their preferred explanation against competing hypotheses. When the three strategies are used at once, the
researcher has triangulated the problem, giving added confidence to
the conclusions of the research. In addition to Mill’s methods of agreement and difference, which he calls “nominal comparison,” qualitative
researchers often use “ordinal comparison” and “within-case analysis.” Ordinal comparison is based on Mill’s (1974:398-406, 883-84)
method of concomitant variation and seeks to establish a rank ordering
of cases based on the degree to which given factors are present. For
example, in Skocpol’s (1979) case, more of the conditions for state
breakdown should be present in the cases of social revolutions than in
nonrevolutions. This means that a single indicator of state breakdown
may be present in the case of a nonrevolution and not present in
a case of revolution, but, in aggregate, in cases in which there are
more conditions for state breakdown, revolutions are more likely. This
is more similar to the logic of variation in most large-N research,
although in practice ordinal logic can be difficult when only a handful
of events are being studied.
The other important strategy that Mahoney (1999, 2000) identified
that is widely practiced in small-N research is within-case analysis.
He identified three major variants: pattern matching (Campbell 1975),
process tracing (George and McKeown 1985), and causal narrative
(Sewell 1996). We focus in this article on the first two.5 Pattern matching is an attempt to see whether all of the various implications of a
theory are actually borne out by the evidence within a case. The more
broadly divergent these implications are, the less likely they are to
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be explained by another theory and the more likely they are to be
explained by the favored theory. This strategy is also looked favorably
on by quantitative researchers who are also interested in qualitative
research like King et al. (1994) because it essentially increases the
number of observations by evaluating multiple implications of the
same hypothesis within a single case.
In process tracing, by contrast, the researcher uses a thick description of the sequence of events of a single case to identify the causal
mechanisms at work in the sequence. This type of method is most
useful when “temporal sequencing, particular events, and path dependence must be taken into account” (Mahoney 1999:1164). Within-case
analysis has been formalized through event structure analysis and used
in both ethnographic (Corsaro and Heise 1990) and comparative historical research (Griffin 1993; Isaac, Street, and Knapp 1994). Withincase analysis methods move away from a variable centered paradigm
and toward a process or narrative paradigm (Abbott 1992).
The combination of Mill’s (1974) methods and within-case analysis
provides a good set of tools for tackling the degrees of freedom problem. By seeing whether various factors are present in all (or almost all)
of the cases of school shootings, one could assess by Mill’s method of
agreement whether they are necessary factors. We can gain additional
confidence in our posited necessary factors by using process tracing to
see whether the hypothesized causes actually played an important role
in the shooting and pattern matching to see whether the hypothesized
causes have all of the effects that our theories suggest that they should.
However, our analytic task differs from that of comparative historicists
both in that the number of negative cases is much greater and that it is
not clear at what analytic level they should be chosen. If we could solve
the comparison case problem and confidently select a representative
sample of near misses, we might be able to establish sufficient conditions. Without these negative cases, we cannot apply Mill’s methods
of difference, and thus we cannot establish sufficient conditions.
THE COMBINED CAUSES PROBLEM
A fourth problem in studying school shootings is that many rare events
result from the combination of causes, or what Ragin (1998) calls
“complexly combinatorial” causation. Because the events are rare but
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the universe of potential cases in which the events might occur is
extremely large, many settings in which the event does not occur are
exposed to many of the same causal factors. For instance, in the case
of school shootings, some of the hypothesized causes are present at the
national level. Examples include the availability of guns and exposure
to media violence. Millions of children in thousands of communities
have access to weapons and are exposed to violence on television, the
Internet, movies, and video games, but only a few commit, attempt, or
plan mass murder in their schools. In this situation, we would like to
allow for the possibility that the explanation involves the combination
of multiple causal factors, perhaps even arrayed in a specific sequence.
How to identify such a theoretical combination of factors is a major
challenge for any research of this kind. We refer to this as the combined
causes problem.
Process tracing is an important strategy for tackling the combined
causes problem. If one argues that an interaction of multiple factors
plays the causal role (rather than a model in which the presence of
certain individual causes makes the outcome more likely), then it will
be much easier to identify such interactions by looking holistically
at individual cases than by looking at variables across cases. Also, by
examining how the different factors come together in making the event
happen, the researcher gains additional confidence in the conclusions.
Of course, this entails the risk of conflating theory building with theory
evaluation, but this problem could be solved by generating theory with
one or two cases and then evaluating it on other cases.
Ragin (1987, 2000) has provided the best explication of the advantages of case-oriented research over variable-oriented research in understanding the role of “causal configurations” as important explanatory
combinations. He argued that in the variable-oriented research common in large-N analysis, the researcher seeks to establish the contribution that a single factor makes to the outcome, controlling for a wide
variety of other variables. Here, the analyst is attempting to understand
the effect of a single cause. Case-oriented research is valuable because
it allows the researcher to understand complex configurations of factors
that may lead to outcomes, even if their subsidiary components are
not individually related to the outcomes. Here, the analyst is trying to
understand the causes of a single effect. In theory, these combinations
can be identified in large-N analyses through interaction effects, but
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SOCIOLOGICAL METHODS & RESEARCH
in practice, when the interaction involves three or more causes, as
real-world phenomena often do, they often cannot be assessed within
large-N research because of problems of collinearity.6
We should note that various other models exist for how to combine
causes. One such model is an additive or multiplicative risk factors
model, in which different factors increase the risk of an event, and
when enough factors are present to move the total risk above a certain
threshold, the event occurs. In this model, the factors are in some
sense exchangeable; it does not matter which factors are present or
in which combination as long as the total risk reaches the threshold.
Note that this is the model presumed in many quantitative analyses of
binary outcomes (such as logit or probit models) in which independent
variables or their interactions additively or multiplicatively increase or
decrease the probability or odds of experiencing the outcome.
THE DIFFERENT CAUSES PROBLEM
A fifth problem occurs when seemingly similar rare events may have
different sets of causes. Perhaps the easiest way to see this is to think
about the role of copycat crimes. Two school shootings may share
similar causes except one; in the second case, the perpetrator got the
idea for the shooting from the prior shooting or copied the form of
the shooting. In the second case, the copycat factor is an important
causal factor, but in the first it is not. It is also possible that two school
shootings may share no causes. In this case, it is reasonable to question
whether the two shootings actually belong to different populations. Of
course, trying to establish whether data are dissimilar enough to be
partitioned into two or more populations of cases is one of the basic
tasks of theory building, whether the events are rare or not, but such
a partitioning may be more difficult when there are only a few cases
with which to work. We refer to this problem as the different causes
problem.
Ragin (1987; see also Ragin 1999) is particularly interested in
how different causal configurations can lead to the same outcome
and thus provide perhaps the most thorough attempt to address the
different causes problem. Ragin drew attention to the fact that most
large N variable-oriented research assumes that causes are always
(probabilistically) necessary and sufficient, such that variation in the
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Harding et al. / STUDYING RARE EVENTS
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independent variable X is linearly related to variation in the dependent
variable Y (see Figure 1a). But in cases in which X is either necessary
or sufficient, the plot will take a triangular form. If X is a necessary
but not sufficient condition, when X is present, Y can be either absent
or present, but when X is not present, there will be no instances
of Y because the presence of X is necessary for the outcome (see
Figure 1b). If X is a sufficient but not a necessary condition, then if X
is absent, Y may or may not occur, but if X is present, Y will definitely
occur because X is sufficient for the production of Y (see Figure 1c).
Ragin’s examples generally focused on sufficient but not necessary
factors for an outcome (e.g., revolutions can come about through rising
expectations or through state breakdown). It is the role of the analyst
to list the combination of present and absent factors in each case and
then to narrow the field to establish the most parsimonious model of
combinations of sets of causes that can explain an outcome.
As previously mentioned, in the case of school shootings, the sheer
number of negative cases in relation to positive cases suggests that
sufficient factors are not likely to be found. Figure 1b likely describes
quite well the data for any causal theory of school shootings. Any set
of factors, like gun access and media violence, will be found in many
youth who do not commit school shootings, and thus they are not
sufficient factors. However, it is quite possible to use Ragin’s (1987,
1999) logic to identify different causal configurations of necessary
factors that explain different types of school shootings.
TWO SCHOOL SHOOTING CASES
As part of a National Academy of Sciences study of lethal school violence (National Research Council and Institute of Medicine 2002), we
conducted in-depth qualitative case studies of the rampage shootings at
Heath High School in West Paducah, Kentucky, on December 1, 1997,
and at Westside Middle School just outside Jonesboro, Arkansas, on
March 24, 1998. These cases were assigned to our research team by
the Case Studies of School Violence Committee. Both meet most scholarly and popular definitions of school shootings. The assailants were
White boys, students at the schools they attacked, with no significant
record of “problem behavior.” The shootings took place in racially
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(A) Linear: X Necessary and Sufficient for Y
Y
::::::::
::::::::
1
0
::::::::
::::::::
0
1
(B) X Necessary but not Sufficient for Y
X
Y
::::::::
::::::::
1
0
::::::::
::::::::
::::::::
::::::::
X
0
1
(C) X Sufficient but not Necessary for Y
Y
1
::::::::
::::::::
0
::::::::
::::::::
0
::::::::
::::::::
1
X
Figure 1:
Ragin Diagrams for Necessary Causes and Sufficient Causes (points represent
cases)
SOURCE: Adapted from Ragin (1987).
186
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Harding et al. / STUDYING RARE EVENTS
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homogeneous, middle- and working-class rural communities. Both
shootings occurred on school grounds, and each had multiple victims
who were also members of the school community. The shootings were
planned in advance and were not motivated by interpersonal disputes
with specific individuals who had wronged the shooters.
Fieldwork was conducted in these communities in May and June of
2001. The research is based on participant observation and qualitative
interviews with almost 200 community members including family
members of some of the shooters; school faculty and administrators;
students and parents; civic, community, and religious leaders; legal and
police officials; and other community members. These data are supplemented by police and investigative materials, court records and depositions, psychological evaluations of one of the shooters, the shooters’
own writings, school district materials, and media reports. The purpose
of our original investigation was to understand the causes of each
shooting, to suggest measures to prevent future school shootings, and
to understand how the communities were affected by the events. We
focus here on causes. We briefly describe these two shootings below.7
Just before the morning bell rang at Heath High School on the day
after Thanksgiving vacation, Michael Carneal, a 14-year-old freshman,
pulled a handgun from his backpack and shot eight bullets into a group
of students gathered for a morning prayer in the school lobby, killing
three and wounding five. He put the gun he had stolen from a neighbor’s
garage on the floor and surrendered to the school principal. Carneal,
later diagnosed with a mild form of depression and the beginning stages
of schizophrenia, complained that he had been teased and picked on
by other students relentlessly and said after the shooting, “People will
respect me now.” While he was not a social outcast and had friends and
even a girlfriend, he was not central to any social group at the school.
Carneal had joked about bringing guns to school and taking over the
school with a small group of peers and had brought a gun to school
and showed it to classmates on two occasions prior to the shooting.
The week before the shooting, the boy whom classmates described
as a jokester and prankster warned some classmates to stay out of the
lobby on Monday morning and that “Something big is going to happen
on Monday.” Carneal is the son of a respected lawyer and homemaker
who were heavily involved in school and church events, and his sister
was one of the school’s valedictorians. He plead guilty to three counts
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of murder, five counts of attempted murder, and one count of burglary
and was sentenced to life in prison without parole for 25 years.
The second incident took place just outside Jonesboro, Arkansas.
Students and teachers were discussing their recent spring break when
Andrew Golden, clad in camouflage clothing, came into Westside
Middle School during fifth period and pulled the fire alarm. Golden
then joined Mitchell Johnson, already in position on a wooded hill
overlooking the school, as the students and teachers filed out of the
school in response to the fire alarm. The 87 students and nine teachers
who exited the west entrance of the building were met with a hail
of gunfire that killed four students and a teacher and wounded 10
others.
Earlier that morning, Johnson stole his mother’s van and picked up
Golden, and the pair stole guns from Golden’s father and grandfather.
They had an elaborate escape plan but were apprehended by police
200 yards from the school about 10 minutes after the shooting. The
day before the shooting, Johnson told peers he “had a lot of killing to
do” and that “tomorrow you will find out if you live or die.” Johnson’s
family had recently moved to Arkansas from Kentucky, although he
was born in Minnesota. His mother, a former corrections officer, was
divorced and remarried, and the family was quite poor. Johnson had
been sexually abused by a neighbor as a child and had an explosive
temper that landed him in some trouble at school. Despite his occasional outbursts, Johnson was generally known by the adults at his
school as an unusually polite boy, who did whatever he could to please
adults. Golden is the son of postal employees. He was not considered a
discipline problem at school but was known to neighbors as a menace,
a boy who rode around on his bicycle with a sheathed hunting knife
strapped to his leg. He was taught to hunt at a young age and was
an expert marksman. Some residents claimed he tortured and killed
cats. Too young for adult court, both boys were sentenced to juvenile
detention until they turn 21, at which point they will be released.
STRATEGIES FOR EXPLAINING SCHOOL SHOOTINGS
The media and scholarly press have advanced almost a dozen hypotheses to account for school shootings such as those at Heath and Westside.
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These include media violence, bullying, gun culture, family problems,
mental illness, biological predispositions, peer relations, demographic
change, culture of violence, and copycatting, almost all of which offer
some element of truth. Here, we explore strategies for making sense
of the causes of school shootings based on in-depth data of the type
gathered in qualitative case studies.
Based on our qualitative case studies of two cases, we propose a
theory of school shootings involving five necessary but not sufficient
factors for school shootings. The development of this theory simultaneously employs two distinct logics of analysis: Mill’s (1974) method
of agreement and within-case analysis.
Mill’s (1974) method of agreement provides the overall logic for
the theory. Each of the five factors is present in the two cases we
studied. Two methods of within-case analysis—process tracing and
pattern matching—convince us that these five factors played important
roles in the shootings. We briefly summarize these five factors here as
they will be important to the rest of our discussion. Further discussion
and systematic empirical justification can be found in Newman et al.
(forthcoming). While some of the five factors may seem tautological
at first glance, their complexity will be revealed through the remainder
of the article.
The first and most obvious factor is gun availability. Clearly, a school
shooting cannot occur unless a youth can attain unsupervised access
to a weapon with which to commit his crime. The critical question is
not whether the school shooter was able to access a gun but the ease
with which youth in the community can get access to guns.
The second necessary factor is the availability and adherence to a
particular cultural script that supports a school shooting. The shooter
must somehow believe that bringing a weapon to school and firing on
his classmates will resolve an important problem, and cultural scripts
provide a model for problem solving. In particular, the cultural script
provides the rationale for a public attack on the institution as a whole
rather than a targeted attack at individual teachers or students whom
the attacker sees as the source of his problems. Such scripts might be
provided by copying a previous school shooting, media violence, a
culture of violence, or notions of masculinity. In the Heath case, for
example, we believe that notions of masculinity and violent media
provided such a script for Michael Carneal.
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SOCIOLOGICAL METHODS & RESEARCH
The third necessary factor is the perception by the shooter of an
extremely marginal social position within social worlds that are important to him. For the Heath and Westside cases, the relevant social worlds
are the adolescent society centered around the school and the tightly
knit rural community. In small communities such as these, the school
itself is the only stage and the center of social activity. Within adolescent society, where identity is closely tied to peer relations and position
in the social hierarchy, bullying and other forms of social exclusion
can lead to marginalization and extreme forms of desperation and
frustration. In a tightly knit rural community, where ties are multiplex,
anonymity scarce, and homogeneity the rule, those who are different
are easily marginalized.
The fourth necessary factor is an individual problem that magnifies
the impact of the shooter’s social marginalization. When a personal
trauma, such as family breakdown, mental illness, abuse, or other
forms of loss, is present, the individual’s emotional and psychological resources for dealing with social marginalization are reduced. In
Heath, Michael Carneal’s mental illness and depression made him
especially susceptible to and sensitive to social marginalization. In
Westside, Mitchell Johnson’s experience of sexual abuse as a young
child and problematic relationship with his father made him especially
susceptible to social marginalization.8
The fifth necessary factor is a failure of the social support systems
that are intended to catch troubled teens before their problems become
so extreme as to lead to a school shooting. In both Heath and Westside,
the organizational structure and culture of the school (structures and
cultures certainly not unique to these two schools) made it difficult for
faculty and staff to identify Michael Carneal, Mitchell Johnson, and
Andrew Golden as potentially violent criminals and intervene to stop
their descent into violence.
Note that the five factors differ in their specificity. For example,
while availability of guns is immediate and concrete, social marginalization is contextual and subjective. Moreover, the actual processes
through which each factor contributes to the school shooting vary with
each case. In this sense, the model is similar to Ragin’s (1987) Boolean
algebra model in which there are multiple paths to the same outcome.
However, in our model, it is not that there are different factors that
could lead to the outcome but rather that within each necessary factor
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Figure 2:
191
Venn Diagram of Five Necessary Causal Factors
there are a variety of substitutable elements.9 Taken together, the five
factors identify theoretical commonalities across cases.
It bears repeating that Mill’s (1974) method of agreement produces
only necessary but not sufficient conditions. Mill’s method of difference (or indirect method of difference) has the potential to produce
sufficient conditions, but because our case studies do not include
schools or communities that did not experience a school shooting, we
cannot use these methods. There are likely many cases that possess
all five factors but that have not experienced a school shooting. However, we do not expect a school shooting to occur in a case in which
the five factors are not all present. This is the conventional meaning
of necessary but not sufficient conditions. This idea is illustrated in
Figure 2, which presents a Venn diagram of the universe of potential
school shooting cases. Each of the five factors is represented by a circle
enclosing all cases in which the factor is present. Only among cases
in the shaded region on which all five circles overlap would we expect
to see a school shooting incident, but not all cases within the shaded
region must have an incident for the theory to be correct.
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SOCIOLOGICAL METHODS & RESEARCH
QUALITATIVE CASE STUDY DATA
Previous researchers with data on many cases have also attempted to
identify common factors across school shooting cases (e.g., O’Toole
2000; Verlinden et al. 2000; Vossekuil et al. 2000). These researchers
have not come up with the same set of factors as we have, however. For
example, Verlinden et al. (2000) discussed 37 risk factors in six broad
categories (individual, family, school/peer, social environmental, situational, and attack-related behaviors) that are common to at least some
of the 10 school shooters they studied.10 We believe this difference is
due to our qualitative case study method, which allows us to look
at meso-level factors such as school organization and community
culture. Quantitative researchers with a larger number of cases are
often limited to factors easily measurable from media accounts, mostly
micro-level factors. Meso-level data are hard to gather using traditional
quantitative methodologies such as surveys because it is a property
of the social system itself rather than the individual and may not
be immediately clear to the individuals embedded within the social
system.11 A few examples will serve to illustrate the value of qualitative
case study data.
An important meso-level phenomenon is the adolescent culture that
left Michael Carneal, Andrew Golden, and Mitchell Johnson feeling
marginalized and angry. Hidden from adult view but closely related
to the local community culture and the actions of adults, the adolescent culture engenders rage in the socially unsuccessful and conceals
threats from adult authority figures in a position to act to prevent
them from being carried out. Two important aspects of adolescent
society were revealed by our discussions with students and faculty.12
First, because young adolescents generally lack internally defined sets
of goals and because externally defined markers of success such as
academic achievement are seemingly disconnected from immediate
real-life consequences, the opinions of others become a primary good
for which adolescents compete. This helps us to understand the strong
relation between status and peer approval in the social world of adolescence. Second and related, because adolescence is a period of identity
establishment and because peers play such an important role in status
hierarchies, finding a place in a peer group is an important aspect
of identity development in adolescence. We observed a stark contrast
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between older and younger youth at Heath and Westside, for example.
Older youth who have grown more comfortable with their identities
had a much lower need for peer acceptance than younger youth.
Within the peer-oriented adolescent culture, bullying, teasing, and
exclusion serve to police the narrow boundaries of appropriate behavior, language, and clothing. Images of masculinity, femininity, and
competence are imported from the wider local and national culture.
Those who deviate from these images are labeled “gay,” perhaps the
most damaging stigma in a conservative small town or rural area.
With an understanding of this context, we set out to map the social
world of each of the two schools we studied. Which social groups do
youth divide themselves into, and to what degree is there a hierarchy
among groups? Where are the shooters located in this social world?
We received a wide array of often-contradictory responses from individuals differently located on the social map but were able to construct
portraits of these worlds by triangulating from the comments of various
respondents.13
For instance, in the Heath case, a group known as the “preps,”
consisting of the cheerleaders, some athletes, and the most physically
attractive students, sits atop the hierarchy. Directly below are a wide
array of groups of relatively equal status such as the Goths, athletes
more generally, “straight arrows” (band members and highly religious
youth), high achievers (socially competent academic achievers), and
“Future Farmers of America” (rural working class). At the bottom of
the pyramid are the druggies, nerds, and vocational education students. The prayer group into which Michael Carneal fired consisted of
students from primarily the high-achiever and straight-arrow groups.
Michael Carneal had attempted to be part of three of these groups—
the high achievers, the straight arrows, and the Goths—but in all three
he failed. He followed his sister’s footsteps into the band, where by
her senior year she was a section leader, but Michael was one of two
students forced to sit out of competitions early in the season because
there were not enough uniforms. Despite the wishes of his parents,
he did not do well enough in class to be a high achiever, although
again this was an arena in which his sister excelled, becoming one
of the school’s valedictorians. He then turned to the Goths, a group
of mostly older students who rejected the wider social norms around
clothing, musical taste, and Christianity that pervade the school. They
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SOCIOLOGICAL METHODS & RESEARCH
sometimes openly clashed with the prayer group, talking loudly during
prayer meetings in the school lobby. In an attempt to fit in, Michael
gave money and gifts, which he claimed were stolen, to members of
the Goth group and to others.
But Michael never seemed to fit in anywhere. He described himself
as a tagalong among those whom others might have considered his
friends and suffered under the shadow of his older sister who was
successful in the social, academic, and extracurricular realms. Whether
correct or not, he believed no one cared about him. His attack on
the prayer circle can be understood within the context of his social
marginalization. While certainly not the whole story behind the shooting and Michael’s marginalization, it is important that Michael was
attacking members of groups that he had failed to enter, the high
achievers and the straight arrows, in another attempt to gain favor with
the Goths. However, he was also attacking an entire social structure
that had left him without a group in which to construct a positive
identity.
The Westside adolescent hierarchy is similar to Heath’s structure
but consists of two tiers instead of three. At the top of the pecking
order are the athletes, the cheerleaders, and a few others who are
graced either with money or, especially for girls, beauty. Below them
come the rest: the band kids, the high achievers, and those that will
in high school become the Future Farmers of America. One or two
students sit outside the social structure entirely and are considered
loners. Like Michael, Mitchell was not a loner, but he was also not
popular.14 While Michael tried to fit into a group he could call his own,
Mitchell aspired not to be a part of a particular clique but simply to
be well liked and popular. Because Mitchell came from a poor family,
he could not gain entry to the top social tier through wealth. While he
did play football and basketball, being an athlete was by no means a
guarantee of popularity. It certainly did not help Mitchell’s popularity
when he was kicked off the basketball team for self-mutilation in the
weeks before the shooting. Moreover when Mitchell bragged about
his supposed exploits on the football field, his fellow team members
publicly and ruthlessly cut him down to size. Mitchell had friends
and even girlfriends, but he had no social group, and most important to Mitchell, he was marginal to the groups he most hoped to
impress.
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In part a response to his social failures, Mitchell tried to carve his
own path and gain respect through other means: He threw gang signs
and used to boast that he had been a member of a gang in Minnesota
and was now a member of the “Westside Bloods.” These attempts,
however, got him nowhere. His peers found it hard to believe that a 13year-old White boy from Minnesota was the seasoned gang member
he claimed to be, so they labeled him a “gang wannabe.” Teachers
also remember Mitchell being overly concerned with his looks, asking
some on several occasions whether he looked good and whether his
hair was well coiffed. But no matter how hard he tried, Mitchell was
not as popular and as liked as he wished he could become. Although
Mitchell was rumored to have had a hit list, Mitchell and Andrew were
more than 90 yards from their victims when they fired indiscriminately
into the crowd of students and faculty. Like Michael, Mitchell was
attacking the entire social structure that had denied him the attention
and the respect he so craved.
In sum, understanding the local adolescent culture in which school
shooters perceive themselves to be slighted and marginalized requires
in-depth, qualitative data. We based our analyses of the adolescent
culture and the place of the shooters within it on participant observation
at school and school events, interviews with students and faculty, and
the statements of the shooters regarding their peer relations. Only
by comparing and contrasting multiple views of the same people,
structures, and events and by probing teenagers about things they see
as seemingly obvious interpretations can we hope to understand the
adolescent cultures of schools and how school shooters fit into them.
WITHIN-CASE ANALYSIS
The identification of the five factors using Mill’s (1974) method of
agreement described above is only made possible by a within-case
analysis of the types described by Mahoney (2000) as process tracing
and pattern matching.
Process Tracing
Process tracing helps the researcher to understand how each of the
five factors operates in a specific case and how the factors interact.
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Examining a school shooting case as a process leads us to seek to
understand the links between stages in the process as well as the links
between the individual actors and the actions taken. Critically important in understanding these processes is understanding the meanings
that individual actors attach to various stages and actions.
We illustrate the value of process tracing by examining how the masculinity script played a role in both the Heath High School and Westside
Middle School shootings. At the heart of Michael Carneal’s shame and
frustration was his inability to establish a masculine identity within
the adolescent society of Heath High School. Interviews conducted
by the police and by psychiatrists following the shooting suggest
that he interpreted the torment he perceived from bullying, teasing,
and exclusion as a direct assault on his masculinity, an important
form of identity, especially in a conservative community. Michael was
distraught that he was unable to stop either the physical bullying from
older or stronger boys or the constant teasing from other peers.
An important part of the assault on his masculinity was an incident in
the eighth grade in which the school newspaper labeled him as gay. Following this incident, Michael’s grades plummeted, and by his account,
the bullying increased and became focused on his sexual orientation.
He was routinely called “gay,” “faggot,” and “pussy.” The magnitude of
these slights was quickly revealed in our interviews with other adolescents in the Heath community, who almost uniformly described being
called gay as the worst possible insult, far worse than being non-White,
poor, overweight, or unattractive. Furthermore, our own observations
in the school and community revealed that the term gay has taken on
a general connotation of incompetence or negativity. Dropping one’s
tray in the cafeteria is “gay,” as is having to stay after school for
detention. In this culture, sexual orientation, masculinity, and competence are closely linked. Furthermore, physical prowess is an important
aspect of masculinity. Michael’s inability to respond to bullying and
teasing effectively only magnified the problem, reinforcing the threat to
his masculinity. Seeking help from adults would not address Michael’s
problem because a “man” handles his own problems.
Police and psychological interviews also revealed that Michael
viewed the shooting as a way to earn respect from his peers. It was an
opportunity for him to assert his masculinity on a public stage, for all to
see. Cultural notions of masculinity identify aggression and physical
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prowess as means of earning and maintaining respect. To be authentic,
respect must be achieved by the individual, not conferred by authority
figures or protectors. Such notions emphasize action over talk, closing
off other potential methods of resolving problems, such as soliciting
help from parents or teachers. Thus, notions of masculinity affected
not just Michael’s perceived marginality but also the form that he used
to address it, a violent attack that, in his mind, could demonstrate to
others that he was worthy of respect. After the attack, Michael told a
psychiatrist that his life was better because “people respect me now.”
In sum, simply knowing that Michael Carneal was bullied and called
“gay” and “faggot” by his peers does not convince us that these events
played a role in the shooting at Heath. Rather, we traced the importance
of these actions by showing how notions of masculinity provided a
script for his school shooting. We examined the meaning of sexual
orientation and masculinity in the local culture and the events that
surrounded the bullying and labeling that Michael experienced and
then examined his own statements to understand how he interpreted
the bullying and how the shooting related to his perceptions of others’
views of his masculinity.
Process tracing also helps to reveal how factors in our model interact
in an individual case. We continue the example of the Heath High
School shooting and Michael Carneal’s perceptions of social marginality to show how his perceptions of marginality were influenced by his
own mental illness, a personal trauma in our five-factor model. In
stark contrast to the account we provide above is information from
interviews with Michael’s peers that he was not teased or bullied
any more than any other students at Heath and that he himself was
somewhat of a bully. Furthermore, Michael appeared to have friends
and even a girlfriend, perhaps the ultimate proof of a young man’s
masculinity.
Michael’s steadily intensifying mental illness explains this discrepancy. Psychologists and psychiatrists who examined or treated
Michael after the shooting diagnosed him with a form of schizophrenia (“schizotypal personality disorder”) and mild depression (“dysthymia”). He had engaged in a pattern of odd behavior, paranoia, and
misinterpretation of social interactions consistent with these disorders
prior to the shooting. He believed assailants were lurking underneath
the floor in his bedroom and peering at him through air ducts in the
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SOCIOLOGICAL METHODS & RESEARCH
bathroom. He covered himself with several towels whenever he went
to the bathroom; often announced, “I know you are in here,” when
entering his bedroom; and hid knives underneath his mattress. He had
unreasonable fears, such as a fear that his family would be robbed if
they went to a restaurant or that he, his father, and a family friend
would be mugged walking across a quiet college campus en route to
a basketball game. He told those who interviewed him that he had no
friends and that he heard people calling him stupid behind his back.
None of these fears and behaviors connected to his mental illness
directly explain why Michael Carneal shot his classmates, but they do
explain why his perceptions of his social position differ from those
of his peers. Michael’s mental illness led him to misunderstand social
relations at Heath High School, magnifying the importance of teasing
and bullying to the point where he believed he was not respected by his
peers and that bringing guns to school was the only way to earn that
respect. In sum, while simply noting that Michael was mentally ill does
not convince us that his mental illness played a role in the shooting, a
closer look at the events leading up to the shooting and the perceptions
of those involved suggests an important role for mental illness. This
example also shows how factors at different levels of analysis can
interact to produce a rare event such as a school shooting. Michael’s
mental illness, an individual-level factor, informed the perceived and
real marginalization within the adolescent culture, a meso-level factor.
Turning to the Westside case, process tracing also helps us to understand how Mitchell’s early violent and repeated sexual abuse by a
neighborhood boy caused him to be especially concerned with his
sexuality, with projecting a masculine image and thwarting any wouldbe attackers. The early abuse clearly left its mark. When he was
11 years of age, Mitchell was caught molesting a 2-year-old, and when
he was 13, he racked up hundreds of dollars of credit card debt on
his father’s card while making sex-talk phone calls. His teachers and
peers also said that Mitchell was unusually preoccupied and invested
in his relationships with girls, once growing despondent enough over
a breakup that he threatened suicide. One staff member recalled that
Mitchell had a bad-boy image and was overprotective of his little
brother, who was also sexually abused by the same neighborhood boy.
One day, Mitchell told her that he felt sorry for his brother because his
brother was “not very tough.” Mitchell’s obsession with projecting an
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image of toughness through his supposed membership in gangs can
be seen as both a way to prove his manhood and as a means through
which he hoped to stave off any further abuse. To ensure his safety,
Mitchell even found himself a protector, making quick friends with
the biggest student in his class. In the same way that Michael’s mental
illness led him to misperceive the social relations at Heath, Mitchell’s
early sexual abuse also caused him to underestimate his own popularity
as well as causing him to be especially sensitive to the attacks on his
manhood.
In the weeks leading up to the shooting, Mitchell started to spiral
downhill; he was kicked off the basketball team (an important avenue in
the adolescent society for popularity), his girlfriend broke up with him,
and his father threatened that he would have to move back to Minnesota
(where he was assaulted) because of his misuse of his father’s credit
card. Like Michael, Mitchell started to threaten his peers, saying that
“something big was going to happen” and that “tomorrow you will find
out if you live or die.” But again, his peers were unmoved, thinking he
was all talk. He might have chosen to direct his anger and pain in any
number of directions: at the boy who had sexually assaulted him, for
example, or at his father with whom he had an especially troubled—
some have even said verbally abusive—relationship. But he directed
his anger instead at the school, at the staff and students who were
obviously unimpressed by his claims to manhood and toughness. The
well-thought-out plan and overwhelming firepower signaled that he
was not all talk and that he and his threats in the weeks before the
shooting should be taken seriously.
In sum, process tracing helps us to understand how Mitchell’s early
sexual abuse and own feelings of insecurity magnified the ordinary
slights and affronts to his ego that are so common within the adolescent
society. It also helps us to understand why earning respect by such
a public display of masculine bravado was very important to him,
providing a script for the shooting.
Pattern Matching
Pattern matching involves examining data to see whether theories
developed from prior research, armchair theorizing, or cross-case comparisons are relevant to a particular case. A theory contains predictions
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about patterns in the data, and with detailed data, these predictions
can be compared with the actual events. Pattern matching differs from
process tracing in that it specifically involves theory testing rather than
theory generation or explication. In practice, however, the two may be
quite similar.
Pattern matching may be particularly useful for examining the role
of macro-level causal factors in a particular case. For a macro-level
cause (such as a regional or national gun culture) to convincingly be
part of a causal account, it must be manifested locally in the particular
event of interest. We take as an example the availability of guns. The
number of guns in the United States has doubled since 1970 to about
200 million (Cook, Moore, and Braga 2001). How is this national trend
manifested in the Heath and Westside communities? While obviously
guns played a role in both the Heath and Westside shootings, is it
fair to say that the easy availability of guns in these two communities
played a role? The gun availability theory predicts that (1) the shooters
will have little trouble identifying a source of weapons and securing
them, and (2) their possession of guns will not serve as a warning
that violence will occur sometime in the future. Conversely, if the gun
availability theory was not relevant, we might expect the shooters to
go to great lengths to find weapons and the possession of weapons by
adolescents to set off warnings among members of the community.
Both these conditions appear to be met in the Heath case. Michael
Carneal was able to identify two nearby sources of weapons. The first
was his father’s pistol and shotguns that were stored in his parents’
bedroom closet; the pistol was in a locked box. Michael stole his
father’s pistol weeks before the shooting and brought it to school to
show to friends, then later gave the gun to a neighborhood youth who
threatened to tell the police he had the gun. Michael’s father did not
discover that the pistol was missing until the police told him they had
recovered it after the shooting. Michael stole the shotguns from his
father the weekend before the shooting and brought them to school
with him the day of the shooting. The second source was a neighbor’s
garage, where a pistol, five rifles, and ammunition were stored in a
locked cabinet. Because Michael had shot guns with the neighbor and
his son, he knew where the key was hidden for the gun cabinet. Michael
stole the pistol from the neighbor’s garage and brought it to school
with him the last day before Thanksgiving vacation. Again he showed
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the pistol to peers, who were reportedly unimpressed because the .22
caliber pistol was “small.” He stole the five rifles on Thanksgiving
Day. The near ubiquity of guns in Heath was also supported by our
interviews with other adolescents, almost all of whom said they could
get a gun if they wanted to.
Although Michael went to great pains to hide the stolen guns from
his family and school officials, his possession of the guns did not
provoke a reaction from other members of the community. As mentioned, he got little reaction from classmates who saw him with guns
in school on two occasions prior to the shooting, despite the fact that
he told people that “something big is going to happen on Monday” and
warned others not to be in the lobby Monday morning. The weekend
before the shooting, he brought the pistol and three of the rifles to a
friend’s house, and the two practiced shooting a pink rubber ball in
the backyard. Their shots woke a neighbor, but he did nothing besides
yell at them to keep quiet. The friend’s older brother, a senior at Heath
High School at the time, also saw the guns and did nothing other than
warn the boys not to get in any trouble.
We see similar but not identical patterns in the Westside case.
Andrew Golden and Mitchell Johnson had only slightly more trouble
securing their weapons than Michael Carneal. The morning of the
shooting, they went first to Andrew’s parents’ house. Most of the guns
owned by his parents were locked in a gun safe, which the boys were
unable to open even with the aid of a blowtorch. They did, however,
take three unsecured pistols from the Golden home. Next, they drove
to Andrew’s grandfather’s house. Andrew’s grandfather was an avid
hunter and had an entire wall of guns secured only by a cable lock.
The boys found a set of cable clippers and cut the cable, taking four
handguns and three rifles. Without Andrew, Mitchell would not have
had such easy access to guns. Because his stepfather had a criminal
record, he was not allowed to have guns in the household. However,
Mitchell did have a gun of his own that was stored at the home of
a family friend. The availability of guns was also supported by our
interviews with Westside adolescents.
In the Westside case, we cannot know whether the boys would have
needed to conceal their possession of weapons had they not used them
almost immediately, but some evidence suggests this might not have
been the case. First, Andrew Golden’s family was well known as an
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avid hunting family, even by area standards. His grandfather worked
for the Arkansas Fish and Game Commission, and his parents ran a
local gun club. Andrew was given his first gun at age six, practiced
shooting at a local shooting range, and won awards for his marksmanship. He brought toy guns to school to play with during recess
and even drew two guns on a school project to design a family coat
of arms—a drawing his teacher later remarked she had thought was
cute because it indicated the family bonded over hunting. It would
not have been unusual for Andrew to have a gun in some situations,
for example, when supervised by an adult on a hunting trip or at
the firing range. Second, Andrew was often seen riding around his
neighborhood on his bicycle with a hunting knife strapped to his leg.
He was known as a menace in the neighborhood, threatening to shoot
other children, and neighborhood children said they saw him killing
cats. While neighborhood parents were concerned enough about this
to forbid their children from playing with Andrew, apparently none of
this was reported to authorities, perhaps because the neighbors were
afraid of the Golden family. Third, the boys made threats at school in
the days before the shooting. The boys told students that they “had a lot
of killing to do” and that “something big is going to happen tomorrow.”
We do not want to overstate the normalization of guns in the Heath
and Westside communities. In neither community would a middle
school or high school student with a gun go unnoticed outside of a
set of narrowly prescribed situations, such as a hunting trip. Certainly,
in this day and age, it would not be acceptable to adults for a youth
to bring a gun onto school property. However, these are communities
in which a significant portion of adolescents regularly uses firearms
for legitimate and legal purposes, mostly hunting. For this reason, it
is not considered unusual, deviant, or threatening for youth to have
weapons. A youth taking target practice in the backyard or carrying a
knife does not provoke an official response because these actions are
not considered predictors of violence, as they likely would be in other
communities.
In sum, the data in both the Heath and Westside cases are consistent
with the theory that the easy availability of guns was an important
factor in these school shootings. This example illustrates how pattern
matching can be used to assess the relevance of a macro-level theory
to a specific rare event.
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DISCUSSION
We now return to the five challenges that frame this article. We consider
the strengths and limitations of our research in light of these challenges
and note possible avenues for future research.
THE CASE DEFINITION PROBLEM
One particular strength of our method is that pattern matching allows
for the possibility of testing the model on other rampage school shootings. This process will help evaluate the generalizability of the findings
from our two case studies. The best source of data is of course other
qualitative case studies of the same type of event. To successfully
employ pattern matching, we must first consider the case definition
problem.
The shootings at Heath High School and Westside Middle School
are both widely accepted cases of school shootings in the national
media. Because school shootings are public events with an established
public discourse, and because we wish to inform this discourse and
the policy that may come out of it, we began with the categories as
they were defined in the public discourse, paying close attention to
the phenomenological nature of such categories and the differences
between seemingly similar cases. But during the course of our research,
as we established the causes of these two particular shootings, we
were better able to define the universe of cases to which these two
incidents belong. Based on the essential aspects of the two cases we
studied and our more limited knowledge of other cases, we identified
the following four characteristics as important in defining what we call
rampage school shootings.15
1. The location of the incident is a “public stage” either on the school
property or at a school-related function.
2. The shooters must be current or former students of the school.
3. There must be multiple victims (although the injuries do not have to
be fatal) or, at the very least, multiple targets.
4. While some victims may be targeted specifically because they have
wronged the shooter, there are typically others who are chosen only
for their symbolic significance (the principal, the preps, the prayer
circle, the jocks) or are shot at random.
Clearly, there are other shootings at schools that would fail to meet
our definition of a rampage school shooting. The Fayetteville case
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described above, for instance, would fail to meet our definition because
there was only one victim (and one target), and the assailant chose his
victim because of an interpersonal dispute over a girl.
At this phase in our research, we are most confident that our theory
applies to other rampage school shootings. However, because we have
studied only two cases in depth, we cannot claim to have tested our
theory on anything approaching a representative sample of cases of
rampage school shootings. The best we can do is attempt to do pattern
matching on other cases.
Qualitative case studies have been done of two other rampage school
shootings: in Conyers, Georgia (Sullivan and Guerette 2002), and in
Edinboro, Pennsylvania (DeJong, Epstein, and Hart 2002).16 While
the data available on these cases are not entirely comparable, we have
examined the studies of these cases, and they are consistent with our
five-factor model. Second to qualitative case study data, the next best
source of data on rampage school shootings is media accounts and
quantitative studies. These sources of data do not have the depth of
information one would like, especially information to do effective
within case analyses.17
One could also compare the causes of rampage school shootings to
the causes of other sociologically similar events that are perhaps less
rare, such as workplace rampage shootings. In effect, this involves
reframing a rare event as a more extreme version of a more common
event. Here, the assumption is that factors causing the rare event and the
more common event are similar enough that something can be gained
by studying the more common event. For school shootings, one might
study other forms of youth violence, delinquency, or suicide to generate
school shooting theories, although we have not yet done so. If school
shootings are similar to other lethal events or extreme manifestations of
nonlethal violence, one might combine these events to increase sample
size and thereby avoid some of the difficulties inherent in small-N
research.
COMPARISON CASE PROBLEM
The public understandably desires a theory of school shooting with
predictive power or at least a profile of school shooters that can help
target preventative resources more effectively. Unfortunately, among
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law enforcement experts, there is consensus that creating a school
shooter profile is impossible (see O’Toole 2000; Vossekuil et al. 2000;
Reddy et al. 2001). One might argue that a serious limitation of our
method is its failure to deliver a model with predictive power. Ideally,
we would find comparison cases of nonevents, which would allow
us to determine whether sufficient causes exist. A theory based on
necessary and sufficient causes would give our model predictive power.
We believe, however, that no such theory will likely ever be developed
because of the difficulty of selecting comparison cases.
Choosing a relevant nonevent can be quite problematic, and depending on the cases one picks, the results can be drastically different. It is
tempting to compare school shootings to the “near misses” that have
made headlines recently, such as the foiled attempt in New Bedford,
Massachusetts, last year in which a group of disaffected students
planned to smuggle guns and explosives into New Bedford High School
to shoot their classmates and faculty. By comparing a school shooting
to a near miss, the analyst can examine the role of the factor or factors
that distinguish the two cases. Foiled attempts tend to be cases in
which the school or other individuals in the community learned of the
plot and were able to successfully intervene so as to avert the tragic
outcome. In New Bedford, one of the students involved in the plot
warned school officials. One might assume that these cases would
have four out of the five necessary conditions present—that is, all
factors except for the failure of social support component. This sort of
a comparison would be illustrative, although there is often no way of
knowing that the shooting would have ever actually taken place short
of a confession.
Yet potentially, there are many other near misses, cases that never
make it to the headlines because they do not involve the intervention
of a third party. For example, potential assailants may not be able to
access the necessary weapons to carry out an intended attack. These
near misses do not make the headlines because the potential shooter
does not make his intentions public. Selecting only certain types of near
misses for comparison will lead the analyst to emphasize only certain
sufficient conditions, potentially leading to incorrect conclusions. The
causes that are sufficient could change with the near miss cases studied.
Near misses are not the only relevant comparisons. One might,
for example, study individuals in the same environment who do not
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commit school shootings, or study schools or communities where
school shootings have not occurred. If we take the former instance
(and thereby attempt to control for meso- and macro-level factors), we
cannot ignore the effect of the shooting on the social dynamics of the
school or community. If we take the latter instance and compare communities where school shootings have not occurred to communities
where they have, we face two serious problems. First, a community that
has yet to have a school shooting is not necessarily a community
that will never have a school shooting. In essence, one would be
comparing communities that have experienced school shootings with
communities that have yet to experience a school shooting.18 Second,
there is a substantial risk that a sample of nonevents is somehow
unrepresentative of all nonevents. While this hazard is also present
when one conducts large-N quantitative studies, the risk of choosing
an unrepresentative sample increases if the sample of nonevents is
small enough to allow for in-depth qualitative analysis.
DEGREES OF FREEDOM PROBLEM
While our method does not solve the degrees of freedom problem,
we think it is misguided to try to isolate the effect of a single cause
in school shootings. Our five-factor model predicts that a change in
a particular factor will not lead to a school shooting unless the other
four factors are present. Thus, trying to estimate the effect of a single
factor controlling for other factors is not only unfeasible, we claim
that it is the wrong way to study this phenomenon. The great strength
of our approach is that a nominal comparison framework allows us
to identify a common set of causes across our two cases, and our
narrative approach ensures that the necessary conditions we identified
were actually important causes in the shootings.
Furthermore, our method does allow us to test competing theories about the causes of school shootings. For example, it has been
hypothesized that bullying is a leading cause of school violence. Our
research suggests that while bullying may contribute to the social
marginalization of youth, by itself bullying is not a necessary cause of
school shootings. More important than any objective metric of abuse is
the way the shooter perceives himself in the adolescent social order—
a perception that may be influenced by bullying or teasing but could
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be influenced by other factors as well. This helps explain why some
of their peers claim the shooters were either not bullied or treated no
worse than were their fellow students. While our methods do not rule
out other factors that may help explain school shootings that we have
not studied in depth, we can rule them out as necessary conditions
since they are not important in our two cases.
COMBINED CAUSES PROBLEM
One possible weakness in developing a complex theory that points
to a combination of causes based on only two cases is that we might
have highlighted a different combination of factors had we started
with two entirely different cases. Indeed, in an ideal world we would
have started with the entire universe of school shooting cases and sent
field teams to each of those sites to do the type of fieldwork we were
able to do in Paducah and Jonesboro. We could then look across all
of these cases and identify the common set of factors using nominal
comparison, process tracing, and pattern matching. Obviously, we do
not live in such an ideal world. Rather, we live in a world that has
school shootings and a world in which social scientists are constrained
by often quite limited resources. Like most qualitative researchers, we
began by building a theory based on a small number of cases and hope
future research will refine it by studying more cases.
An advantage of using the method of agreement is that the necessary factors we identified suggest hypotheses about variation in the
frequency of school shootings over time, space, and social group. Our
model suggests that a change in the prevalence of one or more of our
five factors should be at the source of variation in school shootings
because such a change would increase the number of cases in which all
five factors are present.19 The magnitude of such an increase depends
on the prevalence and distribution of the other factors in the universe of
potential cases, however. If the increase in one factor occurred solely
in cases in which at least one of the other four were always absent, we
would observe no variation.20
DIFFERENT CAUSES PROBLEM
We have identified what we believe is a common set of causes for
rampage school shootings. However, the model says nothing about
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additional causes that may be relevant for individual cases other than
Heath or Westside. Consider a hypothetical school shooting that has
our five necessary conditions but in which the influences of a satanic
cult are also at work—as they are rumored to have been in the Pearl,
Mississippi, shooting.21 Our theory does not preclude the possibility
that additional causes, such as cult influences, are also at work in other
rampage school shootings such as that in Pearl. However, knowing that
cult influences are a factor in Pearl and not in Heath and Westside is
not essential in determining likely points of intervention. One advantage of a model of necessary factors such as our five-factor model is
that it suggests avenues for prevention. If the model is correct, then
intervening in any one of the five areas should be sufficient to prevent
a school shooting, even if additional causes, such as cult influences,
are also at work in other school shootings. As long as we attack any
of the five necessary causes, we are likely to influence the probability
of school shootings.
However, it is possible that our model only applies to a subset
of school shootings and that an entirely different causal model is at
work in some other school shootings. One example is urban versus
rural school shootings. Urban school shootings may not share the
five necessary conditions that we have developed for rural school
shootings. In that case, we might return to our case definition problem
and reevaluate what Heath or Westside is a case of and then divide
the population of school shootings into two: “urban school shootings”
and “rural school shootings.” Finally, it is also possible that our model
applies only to the two cases we have studied in depth, in which
case our theory is not much of a theory. Only by testing our theory
against other cases can we actually determine whether there are really
multiple models or one set of necessary conditions that fits most school
shootings.
CONCLUSION—LESSONS FOR STUDYING RARE EVENTS
When we first began this project, we were quite skeptical about drawing
conclusions from case studies of extremely rare events such as school
shootings and worried that we would be able to provide little more than
a detailed description of the two cases that we studied. In particular,
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we were concerned with five methodological challenges to drawing
inferences from qualitative case studies. These include the difficulty
of defining a relevant universe of cases and identifying comparison
cases, the degrees of freedom problem, and grappling with how causal
factors combine and whether seemingly similar events would have
different sets of causes.
Since then, our views have changed. We hope we have convinced
the reader that it is possible to abstract away from the specifics of
the two cases to develop a theory of rampage school shootings that
suggests avenues for prevention. Borrowing the logics of necessary but
not sufficient conditions and within-case analysis from comparative
historical research, we have attempted to provide a useful theoretical
account of the causes of school shootings based on our qualitative case
studies. This account involves five necessary factors common to both
cases, factors that can be shown to be relevant to each shooting through
process tracing. Pattern matching has allowed us to test the applicability of factors hypothesized to be important to school shootings in
previous research or the popular media. We have rejected some and
accepted others.
A number of other types of rare events share with rampage school
shootings characteristics that pose special challenges for researchers.
These characteristics include extreme rarity, the difficulty of defining
appropriate comparison cases, the potential for causal factors operating
at multiple theoretical levels, and the potential for important interaction
between causal factors. Other types of rare events that likely share
these characteristics include hijackings, suicide bombings, workplace
shootings or other mass murders, riots, mass suicides, coups, political
assassinations, and impeachments, for instance. We believe that the
lessons learned in studying school shootings can be applied to other
types of rare events. To summarize, these lessons include the following:
(1) Valuable conclusions, such as those about prevention, can be drawn
even without comparison cases by focusing on identifying necessary
but not sufficient conditions; (2) qualitative case study data can be quite
valuable because they allow for the connection of causal factors to
outcomes through process tracing; (3) even research involving a small
number of cases can be valuable when it suggests hypotheses for future
research; (4) pattern matching can be used to test the applicability of
theories to individual cases provided the researcher has sufficiently
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detailed data about the cases; and (5) nominal comparison of only a
few cases allows for the researcher to reject some potential necessary
conditions.
Finally, we hope this has provided the skeptic with further evidence
of the utility of small N research. When a complex configuration of
causes operates, the methods described here may have an advantage
over traditional large N methods such as regression analysis because
they can more easily deal with multiple interactions. Take as an example the Venn diagram in Figure 2, imagining that both positive and
negative cases of school shootings appear on the diagram (assuming
for the moment that the issue of defining a universe of cases and
determining appropriate comparison cases has been resolved). If the
five-factor model of necessary but not sufficient conditions is correct,
the positive cases will be concentrated in the shaded region where
the five factors overlap, but negative cases will appear throughout the
diagram, including within the shaded region (since these are necessary
but not sufficient conditions, some negative cases may also have all
five factors).
How would a regression analysis handle these data? If the analyst
suspected that the model involved a five-way interaction, the regression
equation would include the interaction term for the five factors plus the
five factors entered as separate variables. Assuming that our model is
the “true model,” the analyst would find that the interaction term was
nonzero and highly significant, but the other terms were not statistically
different from zero. However, it is hard to see how, in practice, the analyst would ever arrive at the right model, given that standard practice is
to begin with single variables and then test combinations of interaction
terms. In all likelihood, the analyst would end up concluding that each
factor individually increased the probability of a shooting and that
lower order interaction terms did as well, a quite different model than
the “true model” that we posited.22
NOTES
1. A Gallup poll conducted in August 2000 found that 26 percent of American parents feared
for their children’s safety at school. The day after the Columbine shooting, 16 months earlier,
50 percent of parents said they feared for their children’s safety at school. Twenty-nine percent
of 500 high school students polled by ABC News in March 2001 said that they saw some risk of
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an attack at their school, while 40 percent saw some risk immediately following the Columbine
attack. See Gembrowski (2001).
2. The U.S. Secret Service’s National Threat Assessment Center identified 37 school shootings involving 41 attackers that occurred between 1974 and 2000. They chose cases in which
the assailants were current or recent students at the school and in which the attacker or attackers
chose the school “for a particular purpose (and not simply as a site of opportunity)” (Vossekuil,
Reddy, and Fein 2000). The Secret Service report therefore excluded shootings that were related
to drugs, gangs, or interpersonal disputes unrelated to school. The FBI, in contrast, based their
report about school shootings on only 18 cases, which included both successful school shootings
(which they do not define) as well as foiled attempts (O’Toole 2000). Last, the Centers for Disease
Control and Prevention (CDC) recently published a study that was also meant to shed light on
the problem of lethal violence in schools. Their study, however, included all school-associated
violent deaths between 1994 and 1999 and therefore omitted school shootings in which no death
occurred and included acts of lethal violence in which no gun was used. The CDC defined a
case
as a homicide, suicide, legal intervention, or unintentional firearm-related death of a
student or non-student in which the fatal injury occurred 1) on the campus of a public or
private elementary or secondary school, 2) while the victim was on the way to or from
such a school, or 3) while the victim was attending or traveling to or from an official
school-sponsored event. (Anderson et al. 2001:2695)
3. Quantitative methodologists have long been concerned with modeling rare events, but
their procedures are not very helpful in explaining school shootings because these methods
require large databases containing both instances and noninstances of the event of interest.
Their concerns include modeling relationships between events over time, as in Nelson’s (1980)
models of multiple criminal victimization over time or clustering events such as cases of rare
diseases (e.g., Symons, Grimson, and Yuan 1983), selecting appropriate control cases from
among a large group of potential controls in the case-control method (e.g., Lacy 1997; Sanchez
and Higle 1992), and adjusting for biases caused by using standard statistical procedures on
large data sets in which events of interest are extremely rare (e.g., King and Zeng 2001).
4. A reviewer noted that social scientific writing using Mill’s (1974) “method of difference”
might be more aptly characterized as using Mill’s “indirect method of difference.” In the method
of difference, each comparison case is matched on all factors and differs only in the causal factor
and the outcome. This closely approximates the laboratory experiment. The indirect method of
difference is similar to the direct method of difference in that all positive cases have the causal
factor or factors. But the method differs in that no single negative case is matched exactly on
all relevant factors with the positive cases. Rather, the negative cases collectively possess all
the other relevant factors in the positive cases that might account for the positive outcome. (The
negative cases still differ from the positive cases in only the hypothesized cause or causes.) This
method is generally more appropriate for observational data, although Mill argued that neither
method is appropriate for social science. See Mill (1974:388-97, 881-83).
5. Causal narrative involves comparing sequences of events across cases. For example,
Abell’s (1987, 2001) work on comparative narratives showed how processes in different cases
can be compared to derive a common narrative structure of a class of events. While the causal
narrative method could be very useful in studying school shootings, we do not employ the
method in our research because we studied only two cases.
6. When three-way interaction terms are placed in regression models, each of the individual
variables in isolation and then in each possible combination are generally also included in the
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model. For example, if we think that the interaction term X × Y × Z should be in our model,
it is also standard practice to include variables X, Y , Z, X × Y , X × Z, and Y × Z. When all
of those variables and possible interactions are present, however, it is likely that our original
variable of interest, X × Y × Z, will be highly collinear with the other variables (see also Ragin
1999).
7. More details can be found in Harding, Mehta, and Newman (2002); Fox, Roth, and
Newman (2002); and Newman et al. (forthcoming).
8. Unfortunately, we know little about Andrew Golden’s life and cannot confidently evaluate
the problems he was facing at the time of the shooting.
9. Our general model of five necessary conditions written in Ragin’s Boolean algebra is
A × B × C × D × E. However, within each factor, there are multiple elements that might
satisfy the condition. These can be indicated with lowercase letters so that that the model is
(a1 + a2 + a3 + . . .) × (b1 + b2 + b3 + . . .) × (c1 + c2 + c3 + . . .) × (d1 + d2 + d3 + . . .)
×(e1 + e2 + e3 + . . .), where the multiplication sign indicates “logical and” and the plus sign
indicates “logical or.” We thank an anonymous reviewer for this point.
10. Despite the labels Verlinden, Hersen, and Thomas (2000) put on their categories, most
of the 37 risk factors are individual-level factors. For example, the category “school/peer”
includes poor coping and social skills, feels rejected by peers, feels picked on, low school
commitment/achievement, intolerance/prejudicial attitudes, socially isolated, and antisocial peer
group, only the last two of which are actually properties of the school or peer group. Similarly,
the category “social environmental” includes access to firearms, fascination with weapons and
explosives, and preoccupation with violent media/music.
11. Of course, it is possible to measure properties of a social system quantitatively. Usually,
this involves aggregating individual responses or characteristics (as in poverty rates for neighborhoods) or using an individual respondent’s assessment (as in the number of employees at a firm).
Recent efforts have measured “social characteristics” of groups through direct observation. See,
for example, Sampson and Raudenbush (1999) on measuring disorder in urban neighborhoods.
12. These aspects of adolescence were prominently identified by Coleman (1961) and Erikson
(1968).
13. For a discussion of triangulation in contested events, see Roth and Mehta (2002 [this
issue]).
14. For the sake of brevity, we only present information on Mitchell Johnson in this section.
15. For a theoretical justification of our definition of rampage school shooting, see Newman
et al. (forthcoming).
16. The National Academy of Sciences volume that contains these two studies (National
Research Council and Institute of Medicine 2002) also contains case studies of two school
shootings in urban schools (Fullilove et al. 2002; Hagan, Hirschfield, and Shedd 2002). They do
not meet our criteria for rampage school shootings because they were not planned in advance,
and the victims were chosen because they had wronged the offender, not for their symbolic
significance.
17. In Newman et al. (forthcoming), we plan to examine other cases of school shootings to
see whether they conform to our model.
18. In a sense, the same problem can be said to occur when one is comparing countries
that have had revolutions to ones that have not. But the researcher who is studying events or
phenomena as they are unfolding faces different challenges than one whose subject is more
clearly bounded.
19. It is not necessarily the case that variations over time, space, and social group can be
accounted for by changes in the causes of individual events, however. See Lieberson (1997)
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for a discussion of the difference between explaining a distribution and explaining individual
events.
20. For example, an important question about school shootings is why they increased during
the 1990s. One hypothesis is that cultural scripts involving the use of violence are more available
now, perhaps because previous shootings provide a model to copy or because of an increase in
violent video games. A second hypothesis suggests that schools’ ability to identify and aid
troubled youth has declined over time, perhaps because of a gradual shift to larger schools or
more emphasis on high-stakes testing and other “objective” measures of school performance.
Another important question that we do not explore here is why school shootings are occurring in suburban and rural communities and among White boys. Again, the model suggests
that one or more of the necessary factors is more common in these settings or among these
populations.
21. We are not suggesting that cult influences were actually at work in the Pearl case. We
merely use it as a convenient example about our different causes problem.
22. See Ragin (1999) for an extended example.
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David J. Harding is a Ph.D. candidate in sociology and social policy at Harvard
University and a fellow in the Harvard Multi-Disciplinary Program on Inequality and
Social Policy. In addition to school violence, his interests include racial differences in
incarceration, the geographic concentration of poverty, and urban policy as well as
qualitative and quantitative methodology.
Cybelle Fox is a Ph.D. candidate in sociology and social policy at Harvard University,
a doctoral fellow in the Harvard Multi-Disciplinary Program on Inequality and Social
Policy, and a recipient of a National Science Foundation Graduate Research Fellowship.
Her other research interests focus on race, immigration, and the politics of redistribution.
Jal D. Mehta is a Ph.D. candidate in sociology and social policy at Harvard University
and a doctoral fellow in the Harvard Multi-Disciplinary Program on Inequality and
Social Policy. A National Science Foundation graduate fellow, his previous work focused
on the role of social-psychological mechanisms in perpetuating social stratification
and sponsoring social mobility and on racial differences in achievement. His research
interests include combining normative political theory on justice with empirical research
on poverty and inequality.
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