Expert Witnesses, Nonexpert Witnesses, and Nonwitness Experts
Author(s): Michael J. Saks
Reviewed work(s):
Source: Law and Human Behavior, Vol. 14, No. 4 (Aug., 1990), pp. 291-313
Published by: Springer
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Law and HumanBehavior, Vol. 14, No. 4, 1990
Expert Witnesses, Nonexpert Witnesses,
and Nonwitness Experts*
MichaelJ. Saks
The role and responsibilitiesof the expert witness is a controversialsubject.This articleemphasizes
the legal rules (of evidenceandprocedure)governingthe expertandthe policy groundson which they
rest. As the law's policies for the use of expertiseshift from stage to stage as litigationprogresses,or
differbetween categoriesof legal cases (criminalvs. civil), or with a party's use of an expert (from
being a nonwitnessconsultantto an expert witness at trial),the law expects the role of the expert to
be reshapedaccordingly.On some importantissues, the law sends contradictorymessages: Whatits
formalrules announceis at war with its structureand practices.And these, in turn, sometimesare in
tension with the demandsof the expert's professionalethical codes. On other mattersof importance
to experts, the law is silent, because the rules were motivatedby a need to control the behaviorof
partiesand lawyers, not experts. The resultof all this is to presentthose who wouldbe conscientious
expert witnesses with a need to resolve nearlyimpossiblerole conflicts and ethical dilemmas.
In discussingthe problemsof expertwitnessingI am, of course, interestedin what
expert witnesses do, in a descriptionof their behaviorand their interactionswith
other participantsin the legal process. But I am even more concerned here with
the problemof what they "ought" to be doing, of the role the law has carved out
for them, and the tension between the role designed and the part enacted.
Our normativeinterest must go beyond simplisticand extreme moral imperatives, such as "It is bad to lie or mislead," or "It is bad merely to report
knowledge and take no responsibilityfor how the informationwill be used."
Hardlyanyone actuallybehaves at or neareitherextreme, even thoughthe debate
is rhetoricallycast in those terms. Whatwe need to do is to try to understandthe
role of "fact" people in an essentially normativesystem.
* PresidentialAddress, AmericanPsychology-LawSociety, deliveredat the AnnualMeeting of the
AmericanPsychologicalAssociation,New Orleans,August, 1989.Thataddresswas titled "Expert
Witnesses: Psychology and Beyond." Requests for reprintsshould be sent to Michael J. Saks,
College of Law, Universityof Iowa, Iowa City, Iowa 52242.
291
? 1990PlenumPublishingCorporation
0147-7307/90/0800-0291$06.00/0
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SAKS
We are unlikely to find clear answers. The more layers I have managedto
peel away from this topic, the more confused I have become. When I first approachedthis subject, I assumedthat the law had its ideas reasonablywell sorted
out and that experts needed to learn what role the law envisioned for them. But
the more I have inquired,the more I have discovered that the law itself is confused about what it expects of expert witnesses, or has continually changing
expectations. My contribution,then, is to share with you my confusion, which, I
believe, approximatesthe law's confusion.
Old Problems Continually Rediscovered
I first encounteredthe confusion and unhappinessof expert witnesses, as
well as of lawyersandjudges with expertwitnesses, while workingon a book with
Richard Van Duizend, The Use of Scientific Evidence in Litigation (1983). I was
struck by the extent to which modern comment on the problems of expert witnesses echoed earliercomment. Apparentlymany of the difficultieswe face existed long ago and have not improvedwith the years. Here are several illustrations:
The positionof an experton the witness stand,who does not testify eitherto whathe has
observedor knows as fact but expresses merelyhis opinionas to a situationor on facts
which have been establishedby other witnesses, is anomalousin Anglo-Saxonlaw. It
was to be expected that former generationsof judges and lawyers, trained in older
precedents and practices who recognized the appearancein the courts of an expert
witnessas an innovation,wouldlook with suspicionanddoubton such testimony.While
the principleson which suchevidenceis introducedhave come to be well recognizedand
while the [legal]professionno longerhas any reservationsin approvingtheoreticallyof
the use of experttestimony,yet, on the otherhand,there is a constantcomplainingand
mistruston the partof judges,juries andlawyersof the expertwitness. (Friedman,1910,
p. 247)
A generationbefore that, we find the following:
Manyjudges have expressed their thoroughdissatisfactionwith the prevalentmethod
... of makinguse of the servicesof expertsin the conductof judicialinquiries.... [N]o
judgehas, in recenttimes, saidaughtin praiseof the system, so faras the writerhas been
able to observe. Law writersare equallycondemnatoryof the system and severe in their
reflectionsupon the productof that system-the expert. Expertsthemselvesdo not like
it. (Herschel, 1887,p. 571)
And finally:
Of all species of evidenceofferedin a courtof justice, none is so thatchedwith suspicion
or furtherremovedfrom every suggestionof usefulnessas is the evidence of a medical
expert. [They] have so effectuallydiscountenancedthemselves in juridicalestimation
that [to quote]LordChancellorCampbellin the TracyPeerage case [1939, 1843]:"They
come with such a bias on theirmindsto supportthe cause in which they are embarked,
that hardlyany weight shouldbe given to their evidence." Mr. Justice Earl of the New
York Court of Appeals [in Ferguson v. Hubbel, 1884] says: ". . . we think it [expert
medical testimony] should not be much encouraged and should be received only in case
of necessity. [Theirviews] cannotfail to be warpedby a desire to promotethe cause in
which they are enlisted." (emphasisin the original)(Rice, 1898,p. 464).
EXPERTWITNESSES
293
To be Ruled by Judges, by Experts,or by Law?
To furtherset the stage for our problem,let me sharethe following story, not
aboutan expertwitness but about ajudge. WhenI was teachingmentalhealthlaw
several years ago,l some students suggested that it would be enlightening to
observe commitmenthearings.In Massachusettsthese hearingsare not public, so
several phone calls were requiredto find a district court judge willing to let us
attendhearingsin his court. At the conclusion of the hearings,in which everyone
proposed for commitmentwas committed, and after the room had emptied of
everyone but the judge, the students, and me, his honor turned to us and said
approximatelythis:
I guess you noticedthatsome of these peoplewere not fit subjectsfor commitmentunder
the statute.But, afterall, I am a humanbeing. I care aboutwhat is best for these people,
and I have to do what I thinkis right.
This was an extraordinarilycandidjudge. I suppose that if pressed he mighthave
explainedfurtherthat as a complete and caringperson he did not believe he could
be a mere instrumentof the law as set down by the legislatureand interpretedby
the appellate courts, or of the facts presented by the lawyers. His own humanness, his own sense of a right result, yearnedfor expression.
Now, thisjudge presents us with an easy case, because he has a well-defined
and well-recognizedduty to follow the law and to defer to the evidence presented
by the parties-in short, to be, as muchas humanlypossible, an instrumentof the
law, a decision-makingmachinethat applies the law to the facts without regardto
his personal preferences for one outcome or another.2At least within his own
courtroom,thisjudge in effect abolishedthe state's commitmentlaws, substituted
his own, and producedthe result he wanted notwithstandingthe democraticand
legal processes that existed to control these decisions.3 And then, curiously
enough, he as good as told a class of law studentsthat that is what he had done.4
Now suppose we got the same sort of candor from an expert witness. Suppose a hypotheticalexpert turns to the audience after testifying, and says
I guess you noticed that I withheldsome informationfrom the court, stretched other
information,and offered an opinionthat soundedmore certainthan our field's knowledge really permits. I did that because I am committedto makingthe world a better
1 In the
springof 1985at Boston College Law School, jointly with ProfessorCharlesBaron.
To appreciatethat no one actually can accomplishthis feat seems to push people in one of two
directions.Some see it as a challengeto committhemselves to the extraordinarilydifficultresponsibilityof tryingto reach for the ideal. Otherssee it as a license to do anythingthey please.
3 PerhapsI should add that I have known other
judges who apparentlystrugglemightilywith the
tensionbetweenthe dictatesof the law they are requiredto follow and the outcomesthey personally
would like to see in certaincases.
4 Whatthisjudge did reallyis a very old problemfor the law. It is the
problemthat animatesenduring
concernsfor andquestionsaboutthe "ruleof law"-concern by almostall schools of jurisprudence,
demonstrationby legalrealiststhatlaw alonewas not controllingcase outcomes, argumentsby some
criticallegal scholarsthat the rule of law is little more thana delusion, studiesby politicalscientists
modelingwhat is determiningthe choices made by judges, and so on.
2
294
SAKS
place, and I thinkit will be betterif the courtreaches the outcome I want to see in this
case.
One need not look too far to find examples of less explicit but no less imperialistic conduct by real experts. Recently, after hearingan expert witness who
testifies in custody cases perform at a continuing education workshop, I expressed my curiosityat not hearingher mentionany researchor theory that linked
her descriptive testimony of the parents with her recommendationabout who
shouldbe grantedcustody. I asked her if she knew of any studies, any data, any
anythingthat suggests more or less desirableoutcomes for childrenas a function
of which kind of parentwins custody. Tryingto be helpful, she began, "I heard
of someone who was doinga study . .. and you mightcheck with them." I am not
at all sure she understoodwhen I explainedthat I am not the one who needs to
know aboutthose studies, that she is the expert on whom the courts are supposed
to be relying to learn of that knowledge. If all the court needed was someone's
uninformedopinion or guess, they had plenty of their own.
However well intentionedthey are, such imperialexperts display a willingness, first, to disregardwhat knowledge has been developed by the field from
which they claim to derive their expertise and to substitute for that their own
guesses. This amounts to doing to one's own discipline what the Massachusetts
judge was willing to do to the law. And, second, where the assertion of idiosyncratic expertise is chosen strategicallyto bring about a certain result desired by
the expert, then the expert is tryingto do throughan evidentiaryback door what
the Massachusettsjudge did directly:to replace a societal preference expressed
throughthe law and legal process5with one's own preferences.
At a more mundanelevel, there is a need to know the literatureof one's own
field. Not to know it raises the possibilitythat one is not an expert at all, even by
the law's generous definition, and that in turn raises the question whether the
person shouldbe testifyingin the first place. To know the literatureof one's field,
but convenientlyto forgetpartsof it, raises more complex questions that we soon
will reach.
Perhapseven less can be said about other fields. For example, most psychologists probablyare conversantwith the literatureon the predictionof dangerousness and with the reliabilityand validity of diagnosis or psychometric tools, so
that they could advise a court about their imperfectionsand help the fact finder
determinehow muchweight oughtto be given to such predictionsor to testimony
based on such tools. But I have reasonto doubtwhetherexperts in other empirical
fields are similarlywell informed.
For example, recent studies of the "proficiency" of forensic scientists suggest that theirperformanceis less accuratethancommonlyassumed.6The results
Surelythe legal process is an imperfectinstrument.But not as imperfectas a singlejudge or a single
expert installinghim or herself as temporarymonarch.
6 FromPeterson,Fabricant,and Field (1978):71%of police laboratoriesgave unacceptableresultson
a blood test, 51.4%erredin matchingpaint samples,22%could not distinguishamongthree metal
samples,67.8%couldnot identifycow hairs,35.5%erredin soil testing,28.2%madeerrorsin testing
firearms,and so on.
5
EXPERTWITNESSES
295
of most of these studies have not been published. That means that many, and
probablymost, forensic scientists do not know the details. And if they did know,
they are less likely to be asked to reveal that knowledge on cross-examination
because counsel is unlikelyto know aboutthem.7In addition,I wonderhow many
forensic scientists know about the underlyingdata on which their techniques
depend for their validity. Those who do not know are spared worrying about
whethertheir testimony is misleading.Those who do know face the ethical problems associated with knowledge:Do I tell the court things that will undercutmy
own seemingly authoritativeknowledge?(See Symposium, 1989).
POSSIBLEROLESFOR EXPERTWITNESSES
By now I have read articles and books about views of expert witness roles
and experiences that cover an extended time period and a considerablerange of
fields (see bibliographyin Saks & Van Duizend, 1983; Symposium, 1989). The
same complaintsfrom judges and lawyers and the same generally confused or
pained descriptions from experts seem to be independent of era or field. The
extent to which these observers all echo each other impresses me that they are
describing a shared experience, one that is inescapably confusing, but consistently so. The followingare the majoroptions that one sees discussed concerning
what the expert witness could or should be.
Mere Conduit/Educator.If this is the role of an expert, its role occupant
would say somethinglike this:
My firstdutyis to sharethe most faithfulpictureof my field's knowledgewith those who
have been assignedthe responsibilityto make the decisions. To do this may be to be a
mere technocrat,ratherthan a completehumanbeing concernedwith the moralimplications of what I say and with the greatergood of society. The centraldifficultyof this
role is whetherit is all rightfor me to contributehard-wonknowledgeto causes I would
just as soon see lose.
In reviewingChesleret al.'s Social Scientists in Court, Hans (1989)sums up this
role:
[Some] experts embraceda social science normativestance, in which they qualified
statementsmade on the witness stand and discussed evidence againsttheir side: "Adherenceto professionalstandardsis the only thingthatjustifies you beingin court." (p.
312)
Thoughthis soundsbad, andthe presidentof the InternationalAssociationfor Identificationtold
his colleaguesat their annualmeetingin 1978that they had "flunkedanalysis," we mightnote for
perspectivethatthingsdo get worse. Hospitalandcommercialmedicallaboratorieshave been found
by the Centersfor Disease Controlin some of theirqualitycontrolstudies to commitfalse negative
errorsin testingurinefor drugsthatin some studieshave rangedup to 100%(Guerrant& Hall, 1977).
7 I performedLexis and Westlaw searches for
judicial opinions citing the seminalforensic science
proficiencystudy, Petersonet al. (1978),which was publishedas a monographby the Government
PrintingOffice, and as of late 1989I found only two cases that cited the study.
SAKS
296
This type of witness is saying, in essence: They don't want to hear me; they want
to hear my field, of which I am only a representative.
This role's occupant sees the world of litigaPhilosopher-RulerSlAdvocate.
tion somethinglike this:
Thereis a greatergood at stake in this case, and that is (fill in the blank:desegregating
schools, seeing to it that this child goes to the right home, keepingpeople from being
executed, seeing to it that people are executed, etc.). I must advocate for those outcomes, andthatobviouslymeansgivingtestimonythatinvolves clever editing,selecting,
shading,exaggerating,or glossing over.
This role raises the questionwhetherit is all rightto misleadon behalf of a cause
in which I believe.9 Hans (1989)nicely sums up this role as well:
Some experts chose a legal-adversarystance, in which they volunteeredonly research
evidence that supportedtheir side, de-emphasizedor omittedthe flaws in the data, or
refrainedfrom discussingopposingevidence. In the words of one expert,
I understoodthe partisannatureof the courtroomand I realizedthat I would be
on the standarguingfor a positionwithoutalso presentingevidencethat mightbe
contraryto my . .. side. But, you see, thatdidn'tbotherme, because I knew that
the other side was also doing that.10(p. 312)
"Hired gun." This role is much like the one immediatelypreceding, but the
hiredgun works in the service of someone else's values ratherthan advancinghis
or her own. This role sees thejob this way: I mustdo what I can to help the people
who hired me. This style of expert witnessingraises the question of whether it is
all right to mislead in a cause in which one does not believe.
The Fourth Cell in the Matrix. Each of the three roles presented so far
focuses on the central dilemma the expert must confront in relating his or her
field's knowledgeto the cause at stake in the litigation.Each requiresresolving a
conflict between loyalty to one's field of expertise and the outcome of a legal
case.11The Educatormakes the field the first priorityand is impervious to the
claims of the cause on whose behalf it is employed. The Philosopher-Rulerfocuses on the cause and is more or less indifferentto the contents of the field. The
Hired Gun is indifferentto both field and cause, perhaps motivated only by an
altogethertoo obvious thirdvariable.The fourthalternative,in its pureform, is an
8
This is an updatedversion of the "PhilosopherKing."
9 Anotherproblemhere is that the expert witness is givingthe court somethingless than "the whole
truth"that was promisedwhen the expertmountedthe witness stand. Even if the expert canjustify
misleadinga judge or jury in the service of a worthy cause, then why promise to be a conduit/
educator?Tactically,of course, it appearedto be the effective stratagem.Promisingto tell only "the
truth"enhancesthe impactof the witness's fibs. The troublewith that, however, is that over time
judges and lawyers and perhapseven jurors come to view expert witnesses with skepticism. As,
indeed, they have.
0 A statisticianwho served as an expert in a sex discriminationcase we studied put the matter
somewhatdifferently(Saks & Van Duizend, 1983).He likenedthe fact-findingtask of the judge to
tryingto see as much of a matrixas possible, when each side was going to fill in only those cells
favorableto it. The court'sabilityto see the whole picturedependeduponhow completelyand how
well each side filled in its shareof the cells.
Whichmay representcommitmentto a largerideology or may amountonly to commitmentto a
single case.
EXPERTWITNESSES
297
expert witness's heaven on earth: Everythingis in harmony, no dilemmas, you
can have your cake and eat it too. The data are so helpfulto a cause you believe
in that you can be entirelyforthcomingabout them. This fourth cell is a triviality
precisely because it presents no choices. An expert who would testify only under
the harmoniousconditionsof this cell raises a differentethical problem,for which
lawyers have a more ready answer thanwe do.12As a practicalmatter,however,
this cell does not exist. No matterhow good the data are, they never are good
enough for an advocate's purposes. Pressuresmay develop to stretch or to overstate, or to make more clear and unambiguousdata that are never altogetherclear
and unambiguous.
HOW DO PROFESSIONAL AND SCIENTIFIC FIELDS VIEW THE
EXPERT WITNESS'S ROLE?
Variousfields have thoughtabout the part their membersplay when serving
as expert witnesses and in related capacities and in their codes of eithics have
expressed their notion of what members are expected to do. (See Symposium,
1989).Not surprisingly,they emphasizefidelity to the disciplineand resistance to
the partisanpressures of the legal world. Below are excerpts from the ethical
codes of several such disciplines.
The forensic scientist shouldrendertechnicallycorrectstatementsin all writtenor oral
reports,testimony,publicaddresses,or publications,andshouldavoidany misleadingor
inaccurateclaims. The forensicscientist shouldact in an impartialmannerand do nothing whichwouldimplypartisanshipor any interestin a case except the proofof the facts
and their correctinterpretation.(AmericanAcademyof Forensic Sciences, 1989)
Engineersshall issue public statementsonly in an objectiveand truthfulmanner.Engineers shall be objective and truthfulin professionalreports, statements,or testimony.
They shall include all relevantand pertinentinformation.(National Society of Professional Engineers, 1985)
Psychologistshave the responsibilityto attemptto preventdistortion,misuse, or suppressionof psychologicalfindings .... Psychologistspresentthe science of psychology
... fairlyand accurately.... (AmericanPsychologicalAssociation, 1990)
HOW DOES THE LAW CONCEIVE THE ROLE OF THE
EXPERT WITNESS?
Testimonial Experts at Trial
In terms of the formal rules of the legal game, the greatest clarity is to be
found in the law governingtrials. The law13expects expert witnesses to be unbiLawyerswould respondthat it is not ethical to providelegal services only on behalf of causes or
clients of whom the attorneyapproves.
13And here I mean the black-letterlaw-the law on the books ratherthan the patternedbehaviorof
the legal system or the actorsin the legal system. We will come to these otherkinds of law shortly.
12
298
SAKS
ased educators and not advocates. The evidence that this is the law's intention is
plentiful.
First and most obvious, an expert witness is cast in the role of a witness, not
as one of the advocates and not as the decision maker. As with other witnesses,
before being allowed to testify the expert is required to promise to "tell the truth,
the whole truth, and nothing but the truth."14 For the purpose of trying to figure
out what the law wants expert witnesses to be, the typical oath reveals several
things. First, the law seems to know not only about lying but about half truths and
withheld truths, and it wants expert witnesses, like all witnesses, not to engage in
such manipulations. Second, experts are required to take the oath but advocates
are not. That is because experts are there to give evidence and lawyers are not.15
One test of how well an expert has assumed the honest witness role is for a
witness to ask how he or she would answer a question such as this: Please tell the
court everything you know about this case that the party that called you to the
witness stand hopes does not come out during your cross-examination. Would
you openly share the information with the court? Or hide it for the benefit of one
side? Perhaps fortunately, one will rarely if ever be put to such a test, because few
lawyers would risk asking such an open-ended question, especially of witnesses
they are so suspicious of.
To be sure, there are circumstances in which the law protects the right of
people to withhold information, sometimes even to the point of misleading others.
These include a wide array of situations, among them negotiations in business and
in litigation, privacy, trade secrets, and privileged communications. A recent
study by Scheppele (1988) undertook to try to explain the law's rules concerning
when the strategic withholding of information is permissible and when it is not.
This extensive study of diverse cases reports none in which the right of an expert
witness to withhold information from a court was at issue. That such a case could
arise hardly seems likely. The witness is present for the very purpose of supplying
the fact finder with information, has just sworn to do so truthfully and fully, and
faces perjury charges for lying to the court.16 Moreover, any information that
someone thinks a witness ought not to divulge may become the subject of explicit
objections (such as for inquiries into areas of privileged communications), and it
is the court's decision whether the information must be revealed. An additional
and telling point is that the parties, not the expert witness, own the privilege to
suppress information and have the standing to raise such objections. In this conFed. R. Evid. 603 providesthat "every witness shall be requiredto declare that the witness will
testify truthfully."
15
The argumentsof lawyers to the jury at the openingand close of trial are not evidence. And the
questionsput to witnesses are regardedas elicitingevidence, not providingit. That lawyers have
persuasive effect and do supply the jurors with informationthroughthese routes has been the
subjectof psychologicalresearch.(See reviewsin Saks & Hastie, 1978;Hans & Vidmar,1986.)But
that is partof a realistview of the law; in this section we are examiningthe formalview.
16
Fortunately,for the partisanexpert, perjurychargesgenerallycannotbe based upon givingincomplete or unresponsiveanswers, even if that is done with the intentionof misleading.The crossexamineris expectedto ask a sufficientlyrefinedquestionthata pejurious witnesswill makea false
statementin answer.
14
EXPERTWITNESSES
299
text, it would be bizarrefor a witness to possess a "right" to mislead a court.
And, indeed, no one tries to defend such deceptions by saying the law authorizes
them.
Surely in the face of such an explicit forumfor arguingand rulingupon what
a witness must or may testify about, it is not the witness's or one party'sjob to be
deciding what to reveal and what to conceal. The law's theory is that witnesses
keep the advocates honest. And the law has a secret weapon for keeping expert
witnesses honest: the court's power to appointits own expert witnesses.17Were
it up to one side to determine what the witness would say or conceal, then
witnesses would become superfluous.18 Nothing would remainto anchorthe trial
in anythingbut the lawyers' imaginations.The adversaryprocess of dispute resolution and fact finding can work only if all play their parts-judges, lawyers,
jurors, and witnesses. The law's plan works, to at least some extent at least some
of the time. Recall the experts who adopted the "social science normative"
stance, quoted above (fromChesleret al., 1989).Or, to give anotherillustration,
one of the case studies reported in Saks and Van Duizend (1983) involved an
interview with a state prosecutorwho said that he preferredusing local forensic
science experts ratherthan experts from the FBI's crime laboratorybecause, he
said, it was harderto get the FBI's experts to say what you want them to.
In short, the law's formal view of the expert witness is summed up by the
legal aphorism that "A witness is not an advocate and an advocate is not a
witness."
The Roles Defined by the Law are Barely Enforced
The clarity of the formalexpectations about the properrole and behavior of
expert witnesses must not conceal the fact that neitherthe professions nor the law
take much action against experts who violate those expectations. Perhaps this
massive inactionconveys the "real" expectationsof the law and the professions.
Considerthe following evidence.
Duringa recent 8-yearperiod, the AmericanAcademy of Forensic Sciences
received 18 complaints against members-an average of 2.25 per year (Saks,
1989b).Only three involved complaintsof substantivemisrepresentationof facts
underlyingthe expert's opinions:
1. A document examiner who gave an unsupportableopinion received a
formalcensure.
17
Fed. R. Evid. 706 empowerscourts to appointtheir own witnesses. The Advisory Committee's
Note to this rule offers the followingexplanationof the rule's purpose:
Whileexperienceindicatesthatactualappointmentis a relativelyinfrequentoccurrence,
the assumptionmay be madethatthe availabilityof the procedurein itself decreases the
need for resortingto it. The ever-presentpossibilitythatthejudge may appointan expert
in a given case must inevitablyexert a soberingeffect on the expert witness of a party
and upon the person utilizinghis [or her] services.
18
Not to mentionthat the trial system would become purposeless-at least as a fact-findingdevice.
300
SAKS
2. A medical examiner who submittedto courts reports of autopsies that
never actually were performedwas expelled from the AAFS.
3. A forensic scientist accused of misrepresentationof case facts in a paper
presented at a professional meeting was adjudgednot guilty; the ethics
committee concluded that a reasonable difference of opinion accounted
for the conflict.
I also have reviewed the case law involvingcivil law suits and perjuryprosecutions against experts (Saks, 1989b).These cases reveal that most complaints
againstexperts were for giving false educationalcredentials(which was true also
of complaintsfiled with the AAFS ethics committee). 9 Unless the expert witness
is also a fact witness, virtuallyeverythingelse that he or she says on the stand is
either "opinion"testimonyor the basis of that opinion. Opinionsare neithertrue
nor false, and thereforecannot be the subject of "lying."20
Concerningthe basis of the experts' opinions, most experts apparentlyare
smartenough not to stray too far from the bounds of disciplinaryknowledge. By
subscribingto the core knowledgeof one's field, and offeringan opinionbased on
one's "professional"or "scientific"judgment-even an opinionsharedby only a
small minorityof one's peers-an expert witness who overlooks importantcontrarydataor theory or commitserrorsstill is likely to remainsafe from any formal
penalty.
Ironically,ignorancemay only strengthenand protect an expert's testimony.
In one case, I observed a handwritingexpert testify to not knowing about any
studies of handwritingexperts showing that they made a good many errors (cf.
Risinger,Denbeaux, & Saks, 1989). Because the expert did not know about the
studies, they could not be admittedas evidence. Because such evidence would
have undercutthe credibilityof the expert's testimony, ignoranceof those studies
strengthenedthe apparentcredibilityof the expert's opinion. No doubt an analogous benefit has worked for mental health professionalswho, for example, are
unfamiliarwith studies of dangerousnessprediction.One cannot commit perjury
about somethingone knows nothingabout. Ignoranceis not lying.
In short, as the Illinois Supreme Court observed in Sears v. Rutishauser
(1984), "It is virtuallyimpossibleto prosecute an expert witness for perjury"(p.
212).
Expertwitnesses are protectedeven morefully fromcivil liability.Whencivil
suits for damages have been broughtagainst expert witnesses for errors or lies
presentedon the witness stand, those suits have failed because testimonygiven in
court is privileged.Thatis, a witness may say whateverhe or she likes underoath
For a psychologistwho lied aboutcredentialsin the TheodoreBundymurdertrial,see Klinev. State
(1984).For much more on false credentialsby expert witnesses, see Starrs(1987).
20
It may, however,be possibleto show thatan experthas offereda contraryopinionelsewhere, such
as at anothertrialor in a publiclecture. In such a circumstance,it mightbe possible to show that
the expert "lied" concerningwhat his or her opinionactuallywas. While such thingsare possible,
I foundno examplesof themin the cases. The greatestdamagesuch lies may be to the witness who
offersthemis by discreditingthe witness on cross-examination.But findingan expertwitness's past
contradictionsrequiresa level of diligencedisplayedby few attorneys.
19
EXPERTWITNESSES
301
and no privateremediesare availableto persons who may be harmedas a result.21
The only legal remedy availableis a perjuryprosecution.
One case that illustratesthe expert witness's near invincibilityinvolved fingerprintevidence (In re Imbler, 1963;Imbler v. Craven, 1969;Imbler v. Pachtman, 1976). In this set of cases, an object was offered as evidence linking the
defendantto a crime. The object had three fingerprintson it, but the fingerprint
expert reported only the two belonging to the defendant. The third one, which
helped save the defendantfrom a death sentence, was revealed much later. Was
the expert witness dishonest or merely incompetent?Unless one has evidence of
dishonesty, a court must concludethe expert witness was, at worst, incompetent.
Incompetence provides no basis for a perjury conviction. And since no civil
remedy is availablefor harmdone to a person by testifyingin a legal proceeding,
both civil and criminalaction against this expert witness failed.
So far it appearsthat the formalmessage of both the law and the professions
to testifying experts is to tell the complete truth and not to become an assistant
advocate. But then no price is exacted fromthose experts who violate the role the
law and their professionhave definedfor them. The one price the law does seem
preparedto chargefor being untrustworthyis to be deeply suspicious about what
experts have to say. This was evident in our interviews with lawyers andjudges
(Saks & Van Duizend, 1983), few of whom had anything good to say about
experts, as well as in much of the literatureon expert witnesses, some of which
was quoted earlier.
One recent case in which the judicial attitude is made explicit is Tagatz v.
MarquetteUniversity(1988).22 Like other cases allegingemploymentdiscrimination, this one involved the presentationof statistical evidence of disparitiesbetween the behaviorof the defendantemployerand that which would be expected
given the relevant labor pool. But in this case the plaintiffhimself was a "specialist in statistical evidence in employmentdiscriminationcases, preparedthe
statistical evidence on which his case rides," and wanted to serve as his own
expert witness at trial. Accordingto the appellatecourt, "The case is remarkable
because, for the first time ever so far as we know, the plaintifftestified as his own
expert witness." For our purposes, this case presented the curious situation of
one of the most partisanpersonsin the courtroom(the plaintiff)and what officially
mightbe regardedas the most objectiveand disinterestedperson in the courtroom
(the expert witness) being merged into one. The defense objected to this odd
arrangement,but the court of appeals saw no problem:
As Dr. Tagatz'scounsel pointedout at argument,the fact that a partytestifyingas his
own expert is not disinteresteddoes not distinguishhim from any other party who
21
Comparethis to the rule that would applyif the harmfuldeliberatemisrepresentationoccurredoff
the witness stand:"One who fraudulentlymakesa misrepresentationof fact, opinion, intention,or
law for the purposeof inducinganotherto act or to refrainfromactionin relianceupon it, is subject
to liabilityto the otherin deceit for pecuniaryloss caused himby his unjustifiablerelianceupon the
misrepresentation."AmericanLaw Institute(1965), Vol. 2, p. 55.
22
The next three quotationsall come from p. 1042of that opinion.
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testifies in his own behalf;and hiredexperts, who generallyare highly compensatedand by the partyon whose behalfthey are testifying-are not notablydisinterested.
As an aside, note that the judge writingthis opinion was RichardPosner, whose
experience prior to judging came not from being a practicinglawyer but a law
professor who himself sometimes served as an expert witness.
Jurorshave theirown views of the trustworthinessand competence of expert
witnesses. In a survey of formerjurors in Massachusetts, among other findings,
we learnedthat the higherthe educationallevel of a juror, the less competentand
the less honest they thoughtexpert witnesses of all kinds were (Saks & Wissler,
1984).23
The circular ironies in all this are intriguing:Lawyers seeking advantage
select favorableexperts. Experts seeking undue influence cooperate and fudge.
Judges (and at least the better educatedjurors) sharply discount whatever the
expert has to say. The end result may be courts that overprotectthemselves from
being fooled but deprive themselves of knowledge they might have used to improve the decisions they make. In short, the collective cost of reachingfor more
influencethanthe system has allottedis to be accordedless weight than shouldbe
due-all to the long-termdetrimentof experts, litigants, and society.
The Expert Before the Trial
Whatgoes on outside the courtroom,before the trialgets underway,must be
partof the source of insightsinto the role the law has createdfor expert witnesses.
All of the preparationfor a trial-from the decision whether or not to file a case
to the gatheringof evidence and identificationof and preparationof witnesses,
includingexperts, by definitiontakes place before trial. And most cases result in
negotiatedsettlements, never seeing trial. What goes on in the pretrialphase is
controlledless by formal rules than the trial is and more by informalpractices.
The pretrialphase may tell us much about the structureof the legal process and
may reveal its underlyingnorms in ways that a look at the trial does not.
Perhapsthe first thing to notice is that the selection and preparationof experts is by the parties, not by the court. Whereas fact witnesses are limited to
those who have observed the events at issue in a case, expert witnesses come
from a pool that is vastly less limited. Lawyers naturallyand properly(from the
viewpoint of the adversarysystem) seek experts whose testimony will be favorable to their clients. Often they rely on informal networks of communication
amongother lawyers to learnwho mightbe a helpfulexpert witness. If they think
a preliminarychoice unwise, they can dismiss that expert and hire a new one or
several new ones. Some witnesses, such as a party's regularhealth care provider
or one who treatedthe person in an emergency, can serve both as fact witnesses
and expert witnesses. But that in no way prevents an attorneyfrom hiringadditional experts to offer opinions based on the records or the testimony of the
treatingprofessional,or to conducttheir own additionalexaminations.Or experts
on expertise could be hired, who can go into more detail concerningthe under23 Here, then, is
clear evidence of the effects of highereducation.
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303
lying knowledgebase of the primaryexperts. In short, the selection of experts is
not without purpose.
Once an expert is selected, a competent lawyer sets about to secure that
witness's loyalty and cooperation.Lawyers are, after all, professionalpersuaders
and negotiators;they do not reserve those skills for the courtroom. Experts are
introducedto the facts of the case and informedof what is at issue by the lawyer
who seeks their services. Fromthis lawyer, they will learnof the righteousnessof
the case they have been recruitedfor (andperhapsof the evil, distastefulness, or
foolishness of the folks on the other side). Whatthe expert is or is not comfortable
testifyingto at trialis tested out, and, if necessary, negotiatedbetween expert and
attorney.24Moreover, experts learn much of what they know of the law of trials
froma teacherwith a very particularagenda.25By the time they arrivein court the
morning of trial, who is allied with whom is painfully apparent. That anyone
should think that all this will produce a "witness" and not a member of the
advocacy team is itself remarkable.
Let us note, then, that the black-letterrules and the actual processes are at
war with each other, trappingexpert witnesses in the crossfire.
Discovery
In a well-preparedcase, lawyers and experts learn much from each other
during consultations prior to trial. Scheppele (1988) suggests that "the social
distributionof knowledgepermeatessocial relationsfromthe most intimateto the
most impersonal,and much of what we think of as social structuregrows out of
the patterns of hidden and revealed knowledge" (p. 23). If so, then how much
access one side has to the knowledge of the other side's experts should provide
clues to the social structureof trials and witnesses.
The federalrules of civil procedurereflect a dual concern about trials. On the
one hand, the more each side knows about the evidence the other side is going to
present, the more a trial will be a contest over what the evidence means and the
less it will be a "trialby ambush." On the other hand, the system is adversarial,
the parties are encouragedto seek out informationand views beneficial to themselves, to prepare their cases independently, and not to freeride on the other
side's efforts. The rules seek to protect both of these interests. That is accomplishedby makingwitnesses and other evidence subjectto disclosure, but barring
access by one side to the other side's theories and strategy. Thus, the rules of
24
25
An infamousexampleof such negotiationis providedby the prosecutorand the ballisticsexpert in
the case of Sacco andVanzetti.The ballisticianinitiallyconcludedthathis tests did not confirmthat
the murderweaponwas the one that belongedto the defendant.The resultswere inconclusive.But
the prosecutor "negotiated" the ballistician'stestimony into an equivalent yet very differentsoundingversion: that the ballisticsfindingswere not inconsistentwith a theory that the murder
bullets came from the defendant'sgun. The defense was afraidto try to dissect this testimony,
thinkingthat to do so unsuccessfullywould put the defense in an even worse position (Joughin&
Morgan,1976).
Imaginehow differentthe expert'seducationwouldbe if it were handledby a judge or a law teacher
or a lawyer hiredby experts for experts.
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discovery are expansive, generallylimitedonly by whetherthe informationsought
is "relevant" to the subject matterof the lawsuit and whether the informationis
protectedby some "privilege."26In particular,discovery is limitedby an attorney
workproduct doctrine. Protectionfrom discovery of the true advocate's knowledge may serve as a benchmarkfor figuring out whether the expert is to be
regardedas an advocate or an educator.
The Work Product Doctrine
The workproductdoctrineis stated in this language:"In orderingdiscovery
... the court shall protect againstdisclosure of the mental impressions, conclusions, opinions, or legal theories of an attorneyor other representativeof a party
concerninglitigation."27There are at least two reasons to think that the phrase
"other representative"does not includeexpert witnesses. First of all, it certainly
does not include ordinarywitnesses; a great deal of discovery is from witnesses,
and the rules specify the methods by which such discovery is to be carriedout.
Second, additionalrules were developedin 1970specificallyto regulatediscovery
from experts,28to which we turn in the next section.
Many lawyers try to shield experts' reports from discovery by stamping
"work product" on anythingthey receive from the expert. Does that mean the
expert's report equals attorney work product?An attorney who engages in this
practice knows that if the issue of access to the expert's statements ever arises,
the attorneyhas tried to declare much more territoryoff-limitsto the other side
than a judge-or even the attorneydoing the declaring-is going to think really is
insulatedfrom discovery. Lawyers realize that what they say or write often is just
a startingpoint for a debatethey may some day have to engage in, and they do not
for a momentthinktheir startingpoint is likely to be the outcome. A curious side
effect, however, is to make the expert think that the expert's thoughtsare attorney work product,are thereforesecret, and that the expert is an inside memberof
the advocacy team. Some experts mistakenlythinkthat if a lawyer stamps something on a piece of paper it must be so. What may or may not be learnedby one
side from the other side's expert witnesses is controlledby special rules of discovery.
Discovery from Expert Witnesses
Discovery from experts is dividedinto two parts. The first pertainsto expert
witnesses andthe second to nonwitnessexperts. Concerningexpert witnesses, the
rule states: "A party may through interrogatoriesrequire any other party to
Familiarprivilegedcommunicationsincludeattorney-clientor spousalprivileges.Patient-provider
privilegesare waivedvirtuallyautomaticallywhenthe patient'spsychologicalconditionis raisedby
the patientas an issue in the case. And the findingsof physicalor mentalexaminationsare specially
subjectto disclosureunderFed. R. Civ. P. 35.
27Fed. R. Civ. P. 26(b)(3).Examplesof "otherrepresentatives"given by the draftersof the rules are
privateinvestigatorsand insuranceclaim agents.
26
28 Fed. R. Civ. P. 26(b)(4)
EXPERTWITNESSES
305
identifyeach person whom the other partyexpects to call as an expert witness at
trial, to state the subjectmatteron which the expert is expected to testify, and to
state the substance of the facts and opinions to which the expert is expected to
testify and a summaryof the groundsfor each opinion. Upon motion, the court
may order further discovery by other means."29That seems to leave little to
secrecy. Considerthe reasoningbehind the rule:30
Many ... cases present intricateand difficultissues as to which expert testimony is
likely to be determinative.
[A] prohibitionagainstdiscovery of informationheld by expert witnesses produces in
acute form the very evils that discovery has been createdto prevent.
[E]ffectiverebuttalrequiresadvanceknowledgeof the line of testimonyof the otherside.
If the latteris foreclosedby a rule againstdiscovery, then the narrowingof issues and
eliminationof surprisewhich discovery normallyproducesare frustrated.
These considerationsappearto accountfor the broadeningof discovery againstexperts
in the cases cited. ... In some instances, the opinionsare explicit in relatingexpanded
discovery to improvedcross-examinationand rebuttalat trial.
These new provisions. . . repudiatethe few decisions that have held an expert's informationprivilegedsimplybecause of his [or her] status as an expert.
They also rejectas ill-consideredthe decisionswhichhave soughtto bringexpertopinion
withinthe work-productdoctrine.
So far, then, it appearsthat by the lights of the black-letterlaw, expert witnesses
are witnesses, and their knowledge, either duringor prior to trial, is not to be
accorded the protectionthat is providedfor advocates.
Nonwitness Experts
But an expertwho is not expected to be called as a witness, who instead "has
been retained or specially employed," such as to educate or consult with an
attorneyabout a case, is subject to discovery only if the expert has conducted a
physical or mental examination of a party, or "upon a showing of special
circumstances."31First of all, for a psychologistor physicianasked to conduct an
examination, this rule provides little shelter from discovery. Beyond that,
whether and how much informationmay be discovered from such experts is a
subject on which courts are divided. Clearlythe rule exists to serve the complex
purposes of effectively using knowledge in an adversarialsetting. But the exact
contours of the rule are controversialand unclear. (See Day, 1987, 1988;Note,
1982;and one of the few appellateopinions interpretingthe rule, Ager v. Jane C.
StormontHospital (1980),which takes a view contraryto the readingof most trial
courts.)
Fed. R. Civ. P. 26(b)(4)(A)
These quotationsare excerpts from the Advisory Committee'sNotes to the 1970Amendmentsto
Rule 26.
31Fed. R. Civ. P.
26(b)(4)(B)
29
30
306
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In dealing with this rule, courts and commentatorshave wrestled with distinctions among multiple status experts, twice-retainedexperts, second-tier experts, in-house experts, and nonwitness experts (priorto versus after retention).
When is an expert informallyconsulted versus retained? Complex mixtures of
considerationsare taken into account by courts called upon to decide what category an expert is to be placed in. For experts who are deemed notwitnesses,
whatif anythingcan be discoveredaboutthem:Name? Subjectmatter?Opinions?
Basis of opinion?Even to reveal the witness's name mightgive one side a clue to
a line of reasoningabandonedby the other side. If discovery is ordered, should it
apply only to the expert's knowledgepriorto consultationwith the attorney?Or
opinionsthe expert has formedby combiningcase-specific facts with the expert's
priorknowledge?
The theory of the court in Ager is illuminating.That theory is that access to
experts should wax and wane across a series of stages. Prior to consultationby
anyone, the expert is freely available to whomever the expert is willing to talk
with. If an expert has been informallyconsulted, however, no discovery is permitted.Retainedconsultingexperts are availablefor discovery only when unusual
need is shown. Retained testimonial witnesses are fully subject to discovery.
Finally, testimonialexperts in court are, of course, subject to complete examination and disclosure.
A witness who passed througheach of these stages, and at each stage asked
himselfor herselfwhat role the law expected-independent witness or adversarial
teammate-would be led to differentconclusionsat differentstages. A conclusion
drawnfrom one stage would misinformthe expert aboutwhat the law expected of
him or her at another stage. Yet, how would the expert know what category or
stage he or she was in or at? The averageexpert witness has no notion of any of
this. In light of the Ager court's view, and if Scheppele (1988) is right that the
social distributionof informationreveals the social structure,then the law intends
to continuallyrevise the expert's role and relationships. At one stage a fellow
keeper of secrets, at anothera conduit to the enemy.
At each of these stages and with each situationan expert witness is in, the
law's concern is not with a consistent role for the expert; it is with enablingeach
partyto prepareits case withouteitherexcessive hidingof the other side's case or
excessive acquisitionof informationfrom the other side without doing one's own
work.
Considerwhat an attorney faces early in a case that requires technical expertise. The attorney may make several inquiries or even several false starts
before settling on one or more experts whose area of expertise is appropriateor
whose views of the case are favorable.In orderto help the expert understandthe
case sufficientlyto be of help to the attorney,the attorneywill have to share with
the expert some informationand some ideas that the attorneywould not have to
reveal to the other side. Whathappens,then, if this expert is deposed by the other
side? How is the informationthat belongs to an expert, and which is subject to
discovery, to be disentangledfrom the informationthat belongs to the attorney
and is protected by the work product doctrine? What happens to experts an
EXPERTWITNESSES
307
attorney has dismissed as unhelpfulor, worse, unfavorable?Can those experts
become witnesses for the other side?
From the viewpoint of an educator expert, little of this may appearto be a
problem.32The educatorexpertwill be pleased to sharehis or her knowledgewith
anyone who asks for it. And while such an expert has no ethical or legal worry
even about sharing specific opinions on particularaspects of the case at hand
(which the expert learned from the lawyer), the educator expert might at least
consider that if the law does not wish to have attorneywork productrevealed to
the other side, thereis no reasonto thinkthatjust because it comes from an expert
it is any less destructiveof the adversaryprocess. Thus, even the purest educator
expert, who is to be called as a witness, whose knowledgeis discoveredunderthe
applicablerule, still may have at least some adversaryknowledge that he or she
must thinkaboutrevealingto or concealingfrom the "other side." Even for such
an expert, there is no complete escape from the adversarycontest.
From the viewpoint of the attorney, the process of working with experts
presents a majorproblem,because the discovery of expert informationrisks the
release of work product informationalong with it. What some attorneys do to
avoid this, and to strengthentheir cases as well, is to have "clean" experts and
"dirty" experts (Saks & Van Duizend, 1983). The dirty experts are retained as
nonwitnesses, thereby reducingor eliminatingtheir discoverability.Once the attorney learns, with the expert's help, the strongestversion of the cases's technical
facts, a clean expert can be hired to serve as a witness. The clean expert is
informed only of the best features of the case and is told little more than is
necessary to produce the most favorable expert reading of the case, and this
expert is ready for both discovery and trial.
Discovery under the Rules of CriminalProcedure
The rules of criminalprocedure reflect still other concerns and a different
balance to accommodatethose concerns. These include protection of a defendant's constitutionalright against disclosing anythingthat may be incriminating,
concern that criminaldefendantswho learn the details of the case against them
will combat that evidence with false testimony or threatenwitnesses with harm.
The solution of the federal rules is a process of defense-controlledmutuality(tit
for tat exchanges of information).33Any time the defense seeks discovery of
prosecutionevidence, the prosecutionis entitled to obtain comparableinformation from the defense. Informationthat is subject to discovery includes "reports
This discussion is less relevantfor the advocate-expert,who presumablyalready is withholding
informationthat the law expects to be disgorged.That, of course, is the problemon the other side
of this coin.
33 About40 states have statutes
governingdiscoveryin criminalcases, and most of these are modeled
after the federalrule or the ABA Standards.But a considerableamountof variationexists as to
whetherany particularcategoryof informationis somethingthe defendantis entitledto as a matter
of right,or whetherit is controlledby judicialdiscretion,or whetherdiscovery of the information
is precluded(La Fave & Israel, 1985).
32
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of physical or mentalexaminations,and of scientifictests or experiments."34But
not subject to discovery are "reports, memoranda, or other internal . . . documents made by the [defendant, defense counsel, or prosecutor] . . . or by gov-
ernment or defense witnesses."35Thus, the rules of criminalprocedure shield
much more evidence from discovery than the civil rules do, suggesting a more
adversarialskew, and yet they single out much of the informationsupplied by
experts to be made the most accessible.
Black-Letter Rules versus Lawyers' Behavior
Any studentof humanbehavior,includinglawyers, ought not to be surprised
to find that the regularitiesin the behaviorof lawyers andjudges will not necessarily parallel the written legal rules. Several studies have been carried out to
compare the prescriptionsof the rules of civil procedure with the behavior of
practicinglawyers concerningthe discovery of expert witnesses' knowledge(e.g.,
Day, 1987, 1988;Graham,1977).These studies find both consistency and divergence between the rules and lawyers' practices. Here are some examples. Even
thoughthe rules of civil proceduredo not requiremutualityor any constrainton
the timingof discovery, a majorityof lawyersin these studies reportthat informal
norms of conduct reflect such constraints.And though the rules make clear that
the discovery of testimonialexperts is to proceed by a two-stage process supervised by the court (as discussed above), all studies find that the great majorityof
lawyers do not observe the rule. They engage in discovery directly and without
judicial approval.In short, informalarrangementsthat are agreeableto the lawyers sometimes, perhapsoften, supplantthe formallegal rules. This complicates
an expert's life further.Which is "the law"-the words in the law books or the
systematic behaviorof legal actors?
Informal Communication with and among Experts
What restrictions limit the freedom of experts to share their views about
technicalissues relatedto a case with persons other than the lawyer or client who
hired them? Here we are not talkingabout the rights or limitationsof access by
partiesto theiropponents'experts, but the expert'sfreedomto communicate.For
example, if you are an expert, may you discuss a legal case you are workingon
with a colleague?Suppose in the discussion you find out that the two of you have
been hiredby opposingpartiesin the same case. May you talk about the sources
of your differences of opinion in an effort to resolve them? Suppose an expert
dismissedby one partyruns into counsel for the opposingpartyat a social event.
May the expert discuss the case with the other lawyer? Most lawyers routinely
handle these problems by telling all their experts something like this: Before
talking with anyone about this case, check with me. What is the status of this
34 Fed. R. Crim. P. 16(a)(1)(D) and 16(b)(1)(B)
35 Fed. R. Crim. P. 16(a)(2) and 16(b)(2)
EXPERTWITNESSES
309
admonition?Is the lawyer informingthe expert about the requirementsof the law
or merely that lawyer's strategicpreference?
This set of issues brings a fundamentalconcern of many experts-namely,
the open nature of their knowledge and its applications-into conflict with the
attorney's partisanconcern for trying to gain advantageby controllinginformation. While the rules of discovery are intendedto neutralizeprecisely that advantage, the lawyer is obliged to go no fartherthan the rules require. But this tends
to conflict both with the practiceof academicsand other experts to be open about
their knowledge and opinions, and with the practice of health professionals to
consult with each other concerningcases and to seek to resolve differences of
perceptionand opinionby discussingthose differences. These differingpractices
and norms come into conflict in the context of litigation.
The short answer is that no formalrules of procedureor ethics govern these
kinds of communications.On the other hand, lawyers appear to have strong
informalnorms that are widely observed in dealing with "the other side's" experts. Theirnormis thatthey stay away fromeach other's expert witnesses unless
and until they have worked out some arrangementwith each other for such contact. Thus, except underunusualcircumstances,they are unlikely to encountera
player for the "other team." Were that to happen and the informationfrom the
encounter to be used against the adverse party, such sanctions as might be imposed-if any-would be applied to the parties or their lawyers and not to the
experts.
The central point is that, again, we have an example of a cleavage between
the formalrules (which are silent about such communicationsby experts) and the
informalnormsof the legal community(whichrestrictall of these communications
until the lawyer who retainedthe expert has approvedthe communication).
CONCLUSIONS
Decipheringthe role of the expert witness (or, especially, the nonwitness
expert) in the legal process is anythingbut a straightforwardmatter.
The black-letterrules of law are clear enough in their prescriptionfor the
behaviorof experts who are witnesses at trial:They are to be witnesses and not
advocates. And yet the process by which experts are selected, retained, and
preparedfor trialinevitablysocializes them into feeling as if they are membersof
the adversaryteam. The law says be a witness, but the process by which experts
become witnesses sends them the opposite message. Typically, the message that
they owe theirfirst loyalty to the fact findersand not to the party that hired them
is delivered only as they take the witness stand. Yet missing that fundamental
point is unlikely to have immediateconsequences for the individualexpert.
Those same experts, who are expected to be witnesses at trial, are required
to be availablefor discovery by the "other side" prior to trial in civil cases. But
not in criminalcases, unless the defense begins the reciprocalprocess of discovering experts' reports. (And this varies greatly across jurisdictions.)The rules of
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discovery for nonwitnessexperts are unclearand have been little interpreted.The
most authoritativeopinionthat does exist suggests that the role of an expert is to
be continuallyreshapedas the expert moves from one stage to another.
Why the Role Cannotbe Known
The expert role cannot be summedup in any overall terms for a numberof
reasons.
The message suppliedby legal doctrineleads to one conclusion, whereas the
message one gets from the process and structureof the system is quite different.
The tension between the law on the books and the law in practice is quite strong
in this area.
Even if the black-letterrules were to be taken as the authoritativestatement
on what is expected of experts, no simpleanswerfollows, at least for the rules of
discovery. The rules vary across categoriesof law and acrossjurisdictions. Even
the federal rules of civil discovery imply differentroles dependingupon whether
the attorneyintendsthe expertto serve as a witness or a nonwitnessor some other
permutationof uses (which are rarely if ever made known to the expert and
perhapsnot known with any clarity by the attorney).
Regardingsome aspects of the behaviorof experts, the law simply is silent.
This is because the rules are aimed at controllingthe behavior of lawyers, not
witnesses. And they are concernedwith the "other" side's problemof obtaining
information,not each side's problemof hidingits own information.Wherethey do
contemplatethe witnesses, they are concerned with the problem of compelling
unwillingwitnesses to reveal information.The rules of discovery were drafted
principallyto increase the flow of informationto adverse parties and their attorneys. The problemof "too much" communicationis the opposite of the problem
the draftersof the rules were worriedabout. Accordingly,the sanctionsrelatedto
the discovery rules are aimedat punishingpartieswho do not release information
they have been directed to make available.
Whenrule drafterswriterules and courtsinterpretthem, they do not have the
role conflicts of experts in mind. They are concernedwith the problemof making
trialsfair and effective. The shiftinguses which the two sides of a case can make
of an expert are responsive to the tension between the competing goals of the
adversarytrial:to makefull informationavailableto fact findersand to protect the
integrity of the adversarialprocess and independentpreparation.The shifting
amountsof access make sense in that light. But an expert who does not see the
policies behind the waxing and waningof access will be perplexed.
In being responsive to a complex problemin a complex way, the law simply
overlooks the problemit creates for experts by giving conflicting messages and
continuallyrevising its expectations of the expert duringthe process of moving
from the expert's office or laboratoryto the courtroom.The expert is caught in a
tug of war that is at once about the expert and indifferentto the expert.
Consequences
The most immediateconsequenceof being a fact person in a normativeworld
that is adversariallystructuredis to know no consistent or coherent role, but
EXPERTWITNESSES
311
instead to be in a role that receives conflicting messages and changes almost
continually.
This state of affairsdoes not provide an expert witness with a license to do
any old thing he or she wishes, but ratherpresents alternativechallenges:To try
to learnthe complexityof the law in the jurisdictionwhere he or she will serve as
an expert, to read the stage of the case and try to discern which rules apply at
which time, and to balancethat understandingagainstthe informaldemandscreated by the attorneys.Or to hope that one's professionalassociationwill come up
with a set of ethical principlessophisticatedenough to match the law's challenge
and will enforce that code. Or, knowingthat no rules really govern the behavior
of the expert, to decide on what one wishes to say and to whom one wishes to say
it by one's own carefullythought-outprinciples.These are difficultor impossible
options.
Experts who lock on to the earliest signals, given by partisans, will end up
being partisansand will be blamedfor that, as they long have been. Experts who
hold on to their fields' notions of being educator-witnesses will be in constant
tension and continualnegotiationwith the attorneywho has retainedthe expert's
services and will be unlikely to be called on again.
Whereformalrules are barely observed or enforced, informalinfluences are
free to exert a good deal of power. Where no formal rules exist at all, informal
norms surely must rule. These undoubtedlywill be of the adversary'smakingand
will serve the adversary'spartisanpurposes. The expert is free to cooperate or
not. The tendencywill be for those who dislikethe partisancontrolof information
to bow out of legal contests and those who, for whateverreason, enjoy or at least
do not mind it, to be the participantsin the adversaryworld.
The Future
The law and experts themselves create a complicatedand difficult situation
for each other and for themselves. As we have seen, this has not gone unnoticed,
at least for the past century. A leadingwork on the law of evidence states: "It is
not only essential to reduce the partisanelement in the selection of experts, but it
is equally importantthat the contentious character of the presentation of the
results of the expert's investigationbe modified" (Cleary, 1984, p. 44).
Numerous suggestions for improvementshave been proposed, and some
changes in the law have even been made. These include provisions for courtappointedexperts, special masters who will dispose of difficult factual components of cases, and advisoryjuries composed of experts. Althoughthese are on
the books, each of them is used rarely. Some commentators, and the Model
ExpertWitnessAct, suggestpretrialconferencesbetween experts to resolve their
factualdisagreements.This, of course, runsprecisely opposite to the practiceand
the preferences of partisan advocates, and who can blame them. More subtle
influences have been suggested, such as a journal of annotatedtranscriptscommented upon by other membersof the expert's profession. This would bring the
profession'sviews to bear, at least on trialtestimony, keepingexperts from straying too far in the service of "their side," and would provide models for other
312
SAKS
membersof the field (Kaye, 1989).(Professionshave all but left their memberson
their own in the law's alien world.36)
But fundamentalchange in the use of expert witnesses has not taken place
duringa centuryof considerablechangein the law of procedureand evidence. The
law serves the needs it sees as paramount,and it is no doubt sensible to do so. It
does not exist to make expert witnesses comfortable.Instead, it pays them a fee.
Experts can be blamedfor their own behavior. The Model Expert Witness Act,
which would have improvedthe fit between fact-orientedexperts and the normative tensions of the law, was publishedin 1937, and little of it has been adopted
anywhere.Except for theiraginglanguage,the century-oldquotationswith which
this articlebeganprobablywill continueto describe the same problemsa century
from now. On the subject of expert witnesses, one cannot be too pessimistic.
REFERENCES
Ager v. Jane C. StormontHospital& TrainingSchool for Nurses, 622 F.2d 496 (10th Cir. 1980).
AmericanAcademy of Forensic Science (1989). Code of Ethics and Conduct, Article II, AAFS
By-Laws. In AAFS Membership Directory (1989).
AmericanLaw Institute(1965).Restatement(second)of torts. St. Paul, MN: AmericanLaw Institute.
AmericanPsychologicalAssociation.(1990).Ethicalprinciplesof psychologists(as amendedJune 2,
1989). American Psychologist, 45, 390-395.
Chesler, M. A., Sanders, J., & Kalmuss, D. S. (1989). Social science in court: Mobilizing experts in
the school desegregation cases. Madison: University of Wisconsin Press.
Cleary, E. W. (Ed.). (1984). McCormick on evidence, Third Edition. St. Paul: West.
Day, D. S. (1988).Expertdiscoveryin the eighthcircuit:An empiricalstudy.FederalRulesDecisions,
122, 35-61.
Day, D. S. (1987).A judicialperspectiveon expertdiscoveryunderFederalRule 26(b)(4):An empirical study of trial court judges and a proposed amendment.John Marshall Law Review, 20,
377-414.
Fergusonv. Hubbel,97 N.Y. 507 (1884).
Friedman,L. M. (1910).Experttestimony,its abuseandreformation.YaleLaw Journal,19, 247-257.
Giannelli, P. C. (1989). Evidentiaryand proceduralrules governingexpert testimony. Journal of
Forensic Sciences, 34, 730-748.
Graham,M. H. (1977).Discoveryof expertsunderRule 26(b)(4)of the FederalRules of Civil Procedure: Part two, An empirical study and a proposal. University of Illinois Law Forum, 1977,
169-220.
Guerrant,G. O., & Hull, C. T. (1977).Drugabuse proficiencytesting. ClinicalToxicology,10, 209219.
Hans, V. (1989).Expertwitnessing.Review of Chesler,M. A., Sanders,J., & Kalmuss,D. S. (1989),
Social science in court: Mobilizing experts in the school desegregation cases. Science, 245,
312-313.
Hans, V., & Vidmar,N. (1986).Judgingthejury. New York: Plenum.
Herschel, C. (1887).Services of experts in the conductof judicial inquiries.AmericanLaw Review,
XXI, 571-577.
shouldnot overlookis the workof a committeeof the AmericanPsychology-Law
chaired
by StephenL. Golding,which has been developinga set of ethical guidelinesfor
Society,
psychologistswhen workingin forensic settings.
36 One exceptionI
EXPERTWITNESSES
313
Imblerv. Craven,298 F. Supp. 795 (1969).
Imblerv. Pachtman,424 U.S. 409 (1976).
In re Imbler,387 P.2d 6 (1963).
Joughin,L., & Morgan,E. M. (1976). The legacy of Sacco and Vanzetti.Princeton:PrincetonUniversity Press.
Kaye, D. (1989).PersonalCommunication.
Kline v. State, 444 So.2d 1102(Fla. Dist. Ct. App. 1984).
La Fave, W. R., & Israel, J. H. (1985). Criminalprocedure.St. Paul:West.
Lucas, D. M. (1989).The ethicalresponsibilitiesof the forensicscientist:Exploringthe limits.Journal
of Forensic Sciences, 34, 719-729.
Moenssens, A. A., Inbau, F. E., & Starrs,J. E. (1986). Scientificevidence in criminalcases, Third
Edition. Mineola,NY: FoundationPress.
National Society of ProfessionalEngineers(1985). Code of Ethics for Engineers. In R. A. Gorlin
(Ed.). Codes of ProfessionalResponsibility.WashingtonDC: Bureauof NationalAffairs.
Note (1982).Civilprocedure-Ager v. JaneC. StormontHospital:Discoveryof a nontestifyingexpert,
North CarolinaLaw Review, 60, 695-705.
People v. Slone, 76 Ca. App.3d 611, 143 Cal.Rptr61 (1978).
Peterson, J., Fabricant,E., Field, K., & Thornton,J. (1978). Crimelaboratoryproficiency testing
researchprogram.Washington:U.S. GovernmentPrintingOffice.
Peterson,J. L., & Murdock,J. E. (1989).Forensicscience ethics: Developingan integratedsystem of
supportand enforcement,Journalof Forensic Sciences, 34, 749-762.
Rice, F. S. (1898).The medicalexpert as a witness. The GreenBag, 10, 464-467.
Risinger,D. M., Denbeaux,M. P., & Saks, M. J. (1989).Exorcismof ignoranceas a proxyfor rational
knowledge:The case of handwritingidentification"expertise". Universityof PennsylvaniaLaw
Review, 137, 731-792.
Saks, M. J. (1989a).Legal policy analysisand evaluation.AmericanPsychologist, 44, 1110-1117.
Saks, M. J. (1989b).Prevalenceand impactof ethical problemsin forensic science. Journal of Forensic Sciences, 34, 772-793.
Saks, M. J., & Hastie, R. (1978).Social psychology in court. New York: Van Nostrand.
Saks, M. J., & Van Duizend,R. (1983).Theuse of scientificevidencein litigation.Williamsburg,VA:
NationalCenterfor State Courts.
Saks, M. J., & Wissler,R. L. (1984).Legal and psychologicalbases of expert testimony.Behavioral
Sciences & the Law, 2, 435-449.
Scheppele, K. L. (1988).Legal secrets: Equalityand efficiency in the common law. Chicago:University of ChicagoPress.
Sears v. Rutishauser,466 NE 2d 210 (Ill. 1984).
Starrs,J. E. (1987).Mountebanksamongforensic scientists. In R. Saferstein(Ed.), Forensic science
handbook,Vol. II. EnglewoodCliffs, NJ: PrenticeHall.
Symposium(1989).Ethicalconflicts in the forensic sciences. Journalof Forensic Sciences, 34, 717793.
Tagatzv. MarquetteUniversity, 861 F2d 1040(1988).
The Tracy Peerage, 10 Clark& F. 154(1839, 1843).
Thibaut,J., & Walker,L. (1978).A theory of procedure.CaliforniaLaw Review, 66, 541-566.