Human Remains
Determining the Time of Death
A
pathologist can do this most
accurately within the first 24 hours
using algor, livor, and rigor mortis.
 After 24 hours, estimations are made
using environmental factors or other
forensic evidence from the scene.
Algor Mortis
Algor mortis - the cooling of
the body after death.
Generally, the body cools by
about 1 to 1 ½ degrees per hour
from 98.6 degrees at death until
it reaches the environmental
temp.

The
Glaister formula can be
used to determine the number
of hours elapsed since death:
h=(98.4 - internal temp.)/1.5
(Used up to 36 hours after death,
most accurate within 12 hours.)
Livor Mortis
 Livor
mortis – purple or red
discoloration of the body caused by the
pooling of blood after death.
 There is none where the body touches
the ground or is otherwise constricted.
Begins within ½ hour of death
and is most evident at 12 hours,
after which the discoloration will
not change regardless of how the
body is disturbed.

Used to determine whether a
body has been moved.

Rigor Mortis
 Rigor
mortis - the rigidity of skeletal
muscles after death.
 It first appears in the face, neck, and
jaw (small muscles), then in the larger
muscles of the trunk, arms, and legs.
 Occurs within 2 to 3 hours of death
and disappears in approx. 30 hours.
Identifying Skeletal Remains
Forensic Anthropology
 Type
of applied physical anthropology
that specializes in the human skeletal
system for purposes of identifying
unknown remains
A
forensic anthropologist
can use knowledge of the
skeletal system to identify
crime victims and determine
cause and circumstance of death.
Questions to be answered
about skeletal remains
Is it human or animal?
 The
study of bones is called osteology.
 Humans and animals have different
skeletal structures, different bones and
differently shaped bones.
 Microscopically, bones contain holes,
or osteons, that carry blood. Animal
osteons form a regular pattern, while
those in humans do not.
The Human Skeleton
 An
adult human has 206 bones!
 The skeleton provides structure and
protection
 Muscles are connected to bone by
tendons
 Bones are connected to each other
and joints by ligaments
Bones
are classified into four groups:
long - arms, legs, hands, feet
short - wrist, ankle
flat - skull, scapula, sternum, hip,
ribs
irregular - vertebrae, skull
Learn
these…
How tall was the person?
Estimating Height using long bones
Female
(in cm, +/-7.5)
H= femur length x 2.21 + 61.41
H= tibia length x 2.53 + 72.57
H= humerus length x 3.14 + 64.97
H= radius length x 3.87 + 73.50
Male
(in cm, +/-7.5)
H= femur x 2.23 + 69.08
H= tibia x 2.39 + 81.68
H= humerus x 2.97 + 73.57
H= radius x 3.65 + 80.40
Male or Female?
 Using
the Os Pubis—the pelvic bones
have the most obvious differences
between men and women
The pubic arch has a larger angle in
females
The pubic body is narrower in males
The ventral arc is usually absent in
males
 Male
vs. female pelvis
 Using
the
skull—there
are several
differences
between men
and women in
the sizes and
shapes of the
bones in the
skull
Male
Female
Forehead
Sloping
Vertical
Zygomatic
arch
Wide
Narrow
Mandible
Large
Narrow
Male
Female
Chin
Square
Pointed
Ascending
ramus
Wide
Narrow
Nuchal crest
Large, rugged
Small, smooth
Mastoid
process
Large
Small
male
female
Female
Male
How old are the remains?
 An
investigator can reasonably estimate a
person’s age at death by studying the
biological changes that took place during
that person’s life.
 The investigator can estimate most
accurately when teeth are erupting, bones
are growing, and epiphysis (growth
plates) are forming and uniting.
 The
diaphysis makes up most of the
length of the long bone. Epiphyses
are found at both ends; their function
is to allow for growth.
 The epiphyses are good places to look
for changes when estimating age.
Though all people grow at different
rates, there are similarities that make
generalizations possible.
 After
the normal growth period, about
25 to 30 years, age estimation becomes
more difficult and depends on
degenerative changes in the skeleton.
 The
bones of the skull come
together along serrated, interlocking
joints called sutures. These sutures
allow for growth of the skull.
 Closure of cranial sutures in the skull
are also an age indicator. The 3 major
sutures are the sagittal, coronal, and
lamboidal.
 If
the sagittal suture is completely
closed:
Male >26, Female >29
 If the sagittal suture is completely open:
Male <32, Female <35
 If the skull shows complete closure of
all 3 major sutures:
Male >35, Female >50
 Another
way to determine age is to
examine the pubic symphysis - the area
where the two hip bones come
together in front.
 As a person ages, the bones rub
together, producing wear patterns that
range from regular rows
to smooth to
breakdown of bone.
Race Determination?
 There
are three major anthropological
racial groups based on observable
skeletal features:
 Caucasoid—European, Middle
Eastern, East Indian
 Negroid—African, Aborigine,
Melanesian
 Mongoloid—Asian, Native American,
Polynesian
Skeletal Characteristics
 Caucasoid
Long,
narrow nasal aperture
Triangular palate
Oval orbits
Narrow zygomatic arches
Narrow mandible
 Negroid
Wide
nasal aperture
Rectangular
palate
Pronounced zygomatic arches
Longer bones with less
curvature and greater density
 Mongoloid
Rounded
nasal aperture
Parabolic palate
Rounded orbits
Wide zygomatic arches
Pointed mandible
Facial Reconstruction
 When
remains cannot be identified by
traditional means, a forensic sculptor and
/ or artist may try facial reconstruction.
 Steps include:
 Establish gender, age, and race
 Glue tissue markers to landmarks
 Mark muscle insertion points
 Select data set for exact thickness
 Mount
eyes
 Apply clay
 Measure for nose and mouth
 Add details
Proportion is more important than
accuracy in recognition.
Cause of Death and Bone
Anomalies?
 Sometimes
the cause of death is
obvious—stab wounds, bullet holes,
and blows to the head all leave marks
on a skeleton.
 Investigators need to be sure that the
marks were the result of the crime and
not earlier injury or scavenger marks
from animals.
Healed
breaks or fractures,
joint replacements, and
evidence of bone disease can
help in identification.
 Forensic
anthropology uses
osteology, archaeology, pathology,
photography, art and crime scene
investigation in identifying
unknown remains--both modern
and ancient—of victims of crime,
disaster, or unknown causes.