Transcript Forensic Anthropology - Mrs. K's Science Classroom

Forensic Anthropology
What is forensic
anthropology?
• Forensic anthropology is the identification
of skeletal, badly decomposed, or
otherwise unidentified human remains
• Forensic anthropologists frequently work
in conjunction with forensic pathologists,
odontologists, and homicide investigators
to identify a decedent, discover evidence
of foul play, and/or the postmortem
interval.
Why study bones?
• bones often survive the process of decay
and provide the main evidence for the
human form after death
What information can a forensic
anthropologist provide about the
deceased?
• forensic anthropologists work to suggest
the age, sex, ancestry, stature, and unique
features of a decedent from the skeleton
• When skeletalized remains are
discovered, one needs to establish first if
the bones are human
• They can also in certain cases determine
the cause of death
Employment as a Forensic
Anthropologist
• Employment as a Forensic
Anthropologist is as varied as
there are crimes, people and
places
• After the attacks on September
11, 2001, Forensic
Anthropologists were deployed
to a base in Delaware to begin
the tedious process of identifying
bone fragments and teeth.
• They may be called upon to
identify bones and bone
fragments sitting in boxes in
universities and museums.
The Human Skeleton
Determining Sex and Race
•
Male
Female
Size
Large
Small
Architecture
Rugged
Smooth
Palate
Larger, Broader,
U-Shaped
Small, tends to be
a parabola
Supraorbital
Margin
Rounded
Sharp
Large
Small
Mstoid aProcess
Determining Age
– The best bet in determining the age of a sub-adult
skeleton is examination of the teeth and jaw,
when present.
Calculating Height and
Weight
Stature
Weight
3.26 x (humerus) + 62.10 = stature +/4.43cm
3.42 x (radius) + 81.56 = stature +/-4.30
3.26 x (ulna) + 78.29 = stature +/-4.42
Wt (in lbs) = 4.4 x (stature in inches) - 143
Estimating Time of Death
• The first question to be asked and probably the
most difficult to answer is "how long has it been
dead?“
• Bones do not decay as skin and soft tissue do, but
they are subject to weathering and scatter
(taphonomy).
• Animal scattering of bones can destroy the context
of the crime scene and gnaw marks destroy actual
bone
• If a body is buried, insects cannot get at it, but
micro-organisms can. The acidity of soil will have
an effect on bone.
Time of Death Continued…
• Condition of bone depends on the type of burial or
exposure along with temperature.
• When a body is left on the surface, insect activity will
begin immediately and within 2 weeks the body will be
partially skeletalized, completely skeletalized within 8
months.
• If buried, it will take between 1 and 2 years to become
completely skeletalized and in arid areas may become
mummified.
• The number and types of bones available at the scene
indicates the amount of time the body has been in that
spot, i.e. smaller bones get lost first.
Manner and Cause of Death
• Manner of death refers to the 5 possibilities: homicide,
suicide, accidental, natural and unknown.
• Cause of death refers to injury or disease, or combination,
that results in death and could take months/years.
• Determining the cause of death is easier with a fleshed
body and very difficult with the flesh and organs gone.
• Taking X-rays of the skeletal material is very important.
• Damage from metal objects leaves fragmented metal or
metal shavings and saw tooth shavings will show up
bright white on X-ray. Bullets will leave fragments of lead.
Types of Fractures
Type of Fracture
Characteristics
Complete
broken all the way through
Incomplete
crack; not all the way
Comminuted
piece not with the bone
Linear
pressure on skull, stress released by
cracking; soft blunt weapon
Stellate
star-shaped piece missing; hard blunt
weapon
Depressed
usually with stellate, piece pressed in;
hard blunt object, sometimes sharp
weapon
Broken Hyoid
if not adult, not fused; may indicate
strangulation
Timing
near cracks do not cross prior cracks;
indicate order of attack