Title: Human Remains
1Forensic Entomology
2Taxonomy Classification of Things in an Orderly
Way
We are interested in the phylum, Arthropoda
class, Insecta order
Coleoptera (beetles)
Diptera (flies)
3Forensic Entomology Involves the use of insects
and other arthropods to aid in legal
investigations. Entomology is the study of
insects.
There are three areas of application
Insect damage to structures Infestation of
foodstuffs Insects that inhabit human
remains (focus of this chapter)
4The Process of Death
Algor Mortis Body cooling rate Hours
since death 98.4F internal body
temperature 1.5
Livor Mortis skin discoloration caused by
pooling of blood
Rigor Mortis rigidity of skeletal muscles
Temperature of body Stiffness of body Time since death
Warm Not stiff Not dead more than 3 hours
Warm Stiff Dead between 3 and 8 hours
Cold Stiff Dead between 8 and 36 hours
Cold Not stiff Dead for more than 36 hours
A pathologist estimates time of death from these
factors.
5The Process of Death, continued
Stage Description
Initial or fresh decay (autolysis) The cadaver appears fresh externally but is decomposing internally due to the activities of bacteria present before death (04 days).
Putrefaction or bloating The cadaver is swollen by gas produced internally, accompanied by the odor of decaying flesh (410 days).
Black putrefaction Flesh of creamy consistency, with exposed body parts black. Body collapses as gases escape. Fluids drain from body. Odor of decay very strong (1020 days).
Butyric fermentation Cadaver drying out. Some flesh remains at first cheesy odor from butyric acid (2050 days).
Dry decay (diagenesis) Cadaver almost dry slow rate of decay. May mummify (50365 days).
6Life Cycle of Insects
Metamorphosis egg larva (maggot)
pupa winged adult
The life cycle of Musca domestica
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8Time of Death
Insects arrive at a decomposing body in a
particular order (succession) and then complete
their life cycle based on the surrounding
temperature. By collecting and studying the types
of insects found on a body and their metamorphic
stage, a forensic entomologist can estimate the
time of death.
9Insects of Death
Diptera
First to arrive
Then
Flies can arrive within minutes. They lay eggs
that hatch to maggots. Maggots feed on soft,
mushy body parts. More insects arrive to feed on
the body and each other.
10Insects of Death, continued
Coleoptera
In rough order of appearance, from within hours
to dry decay
Sexton beetle
Rove beetle
Clown beetle
Hide beetle
Dermestid beetle
Some beetles feed on the corpse, some on maggots,
some on other beetles.
11Variables Affecting Metamorphosis
Temperature
The higher the temperature (within limits), the
faster the growth.
12Variables Affecting Metamorphosis, continued
Habitat
Fly species can vary geographically according to
climate, season, and habitat.
Phormia regina
Lucilia illustris
For example, the fly pictured on the left prefers
shade the one on the right, sunlit areas.
13Other Applications of Forensic Entomology
Damage to structures, clothing,
foodstuffs Location of wounds on a corpse Linking
suspect to scene of crime Source of
contraband Type of insects can trace vehicle
movement Presence of drugs in corpse
14Collection of Evidence
15Human Remains
16Forensic Anthropology
Forensic anthropology is a type of applied
anthropology that specializes in the changes and
variations in the human skeleton for the purpose
of legal inquiry.
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18Forensic Anthropology, continued
A forensic anthropologist may provide basic
identification information on skeletonized or
badly decomposed remains. From a whole bone or
part of a bone, the scientist may be able to
determine
- An age range
- Sex
- Race
- Approximate height
- Cause of death, disease, or anomaly
19Osteology
- Osteology is the study of bones.
- There are 206 bones in an adult human.
- Function of bones
- Provide structure and rigidity
- Protect soft tissue and organs
- Serve as an attachment for muscles
- Produce blood cells
- Serve as a storage area for minerals
- Can detoxify the body by removing heavy metals
and - other foreign elements from the blood
20Estimation of Height
- The height of a person can be calculated by
measuring the length of certain long bones,
including the femur, tibia, humerus, and radius.
Below are the equations used to determine average
measurements for both male and female. (All
measurements are in centimeters.)
Male Height, H H femur ? 2.23 69.08 H
tibia ? 2.39 81.68 H humerus ? 2.97 73.57 H
radius ? 3.65 80.40
Female Height, H H femur ? 2.21 61.41 H
tibia ? 2.53 72.57 H humerus ? 3.14 64.97 H
radius ? 3.87 73.50
21Age Determination
- Most accurate estimations are made from
- Teeth
- Epiphyses or growth plates
- Pubic symphysis
- Cranial sutures The three major cranial sutures
appear as - distinct lines in youth and gradually close from
the - inside out.
- Investigators always use an age range because of
the variation in people and how they age. The
investigator does not want to eliminate any
possibilities for identification.
22Age By Teeth
23Cranial sutures
24Age Determination Using Cranial Sutures
Sagittal suture
- Sagittal suture completely closed
- Male26 or older
- Female29 or older
- Sagittal suture completely open
- Maleless than 32
- Femaleless than 35
- Complete closure of all three major sutures
- Maleover 35
- Femaleover 50
Lambodial
Coronal
25Age Determination Using Basilar Suture
- Basilar suture
- Technically known as the synchondrosis
spheno-occipitalis, closes in females as young as
14 and in males as young as 16. If the suture is
open, the individual is generally considered to
be 18 or younger.
26Age Determination
- In long bones, the diaphysis, or shaft, makes up
most of the bones length. The epiphyses are
found at the ends of the bones their function is
to allow for growth. The epiphyses are good
places to look for changes in estimating age.
Though all people are different and grow at
different rates, there are similarities that
allow for generalizations in estimating age.
27Definitions
- Stage 1 no epiphysis (the growth plate has not
formed yet) - Stage 2 non-union the epiphysis and bone are
separate - Stage 3 partial union the epiphysis is
attached, but a line is visible - Stage 4 complete union the epiphysis is
attached and a line is not visible
28The Medial Clavicle in Stages 14
29Age Determination Using Epiphysis
Stage of Union of Medial Clavicle Male Female
Non-union without separate epiphysis 21 or younger 20 or younger
Non-union with separate epiphysis 1621 1720
Partial union 1730 1733
Complete union 21 or older 20 or older
30Gender Differences in Bones
- Determination of sex is crucial to the analysis
of unidentified human remains. The pelvis offers
the most definitive traits. Comparison of three
characteristics of the os pubis gives the
information used to identify sex.
Male Pelvis
Female Pelvis
31Gender Identification
A. The female (top) has a wider pubic body
than the male (bottom).
B. The female has a wider subpubic concavity or
subpubic angle.
32Gender Identification, continued
C. Most females have a ventral arc present.
33Human Remains
Male Female
Subpubic Angle
18
34Determine which are male and which are female.
35 Gender Differences
- The rib cage and shoulders of males are generally
wider and larger than those of females. In
addition, about one person in 20 has an extra
rib. This is more common in males than in
females.
36Skull Gender Differences
37Gender Differences, continued
- In males, the index finger is sometimes shorter
than the third finger. In females, the index
finger is sometimes longer than the third finger.
This is not often used as an indicator of gender,
as there are many exceptions.
Is this a male or female hand according to the
above rule?
38Race
- Race is difficult to determine from most skeletal
remains, especially since pure races are becoming
uncommon. An experienced forensic anthropologist
can generally place skulls into one of three
groups - CaucasoidEuropean, Middle Eastern, and Indian
descent - NegroidAfrican, Aborigine, and Melanesian
descent - MongoloidAsian, Native American, and Polynesian
descent
39Race Characteristics
- Caucasoidshave a long, narrow nasal aperture, a
triangular palate, oval orbits, narrow zygomatic
arches, and narrow mandibles. - Negroidshave a wide nasal aperture, a
rectangular palate, square orbits, and more
pronounced zygomatic arches. The long bones are
longer, and have less curvature and greater
density. - Mongoloidshave a more rounded nasal aperture, a
parabolic palate, rounded orbits, wide zygomatic
arches, and more pointed mandibles.
40What differences do you notice among these three
skulls? Can you determine race?
41Facial Restoration
- After determining the sex, age, and race of an
individual, facial features can be built upon a
skull to assist in identification. Erasers are
used to make tissue depths at various points on
the skull. Clay is used to build around these
markers, and facial features are molded.
42The Body Farm
- The Body Farm is the nickname of a
two-and-a-half-acre research facility in
Tennessee developed in 1980 by Bill Bass where
bodies are placed in various conditions and
allowed to decompose. Its main purpose is to
observe and understand the processes and
timetable of postmortem decay. Over the years it
has helped to improve the ability to determine
time since death in murder cases. - Hic locus est ubi mortui viveuntes docent.
- This is the place where the dead teach the
living.
43Anthropologist at Work
- This anthropologist is
- hard at work dusting
- away material from
- these embedded bones.
- Picture taken at
- Chicagos Museum
- of Natural History
44More Applications
Forensic experts may be called upon to give
information on the life and death of humans and
animals in unique circumstances, including
Mass murder (Oklahoma bombing, plane crashes,
World Trade Center) Earlier man (mummies, Iceman,
Lindow Man) Historical significance (Holocaust,
uncertain death of famous people) Prehistoric
animals (dinosaurs)
45Animal Facial Restoration
Determining what T. Rex looked like using the
bone formation. From this To this
46Forensic Pathology
47Forensic Pathologist
- Forensic Pathologist - investigates sudden,
unnatural, unexplained, or violent deaths. They
usually perform autopsies to determine cause of
death - 4 yr. Degree Med School Residency Medical
Pathology Training (2 years) - Work in hospitals or as medical examiner
48Pathologist Conclusions
- Five Conclusions drawn for investigation
- Natural
- Homicide
- Suicide
- Accident
- Undetermined
49Forensic Pathologist
- Way time of death are determined
- Algor Mortis - loss of body heat
- Livor Mortis - 0-12 hours, settling of blood
- Rigor Mortis - 24-36 hours, muscles relax and
become rigid - Potassium levels on ocular fluid
50Livor Mortis Lividity
51Rigor Mortis
52Pathologist v Coroner
- Coroner is elected official no requirements
exist, most funeral people - Historically they solved crimes
- Power to call grand jury
- Being eliminated in other states
- Georgia still has position, county decision
- Fulton does not have a coroner
- Mostly shuffles paperwork, defers to medical
examiners office
53When notice to coroner/medical examiners office
is required
- Death is
- Violent
- Suicide
- Sudden w/ apparent good health
- Unattended by physician
- Suspicious, especially under 16 yoa
- Under 7 yoa unless expected
- Execution
- Inmate of state facility
54When notice to coroner/medical examiners office
is required
- Once notified they decide if further
investigation is needed - Autopsy a possibility
- Required in under 7 yoa
55Autopsies
- Means - see for yourself
- Purpose is to learn the truth about the person's
health during life, and how the person really
died - 2 types medical forensic
- "Hic locus est ubi mors gaudet succurrere vitae
- "This is the place where death rejoices to teach
those who live
56Autopsies
- Religious Issues
- Orthodox Jews usually require Rabbi present,
very resistant to autopsies - Muslims also resistant
- State has power to ignore religious concerns
57Autopsies Method
- examine the outside of the body
- body is opened using a Y-shaped incision from
shoulders to mid-chest and down to the pubic
region - top of the skull is removed, and the brain is
very carefully cut free - breastbone and attached rib cartilages are
removed - chest organs, including the heart and lungs, are
inspected
58Autopsies Method
- take blood from the heart to check for bacteria
- blood, urine, bile, or even the fluid of the eye
used for chemical study and to look for medicine,
street drugs, alcohols, and/or poisons - After any organ is removed, the pathologist will
save a section in preservative solution
59Autopsies Method
- Organs are all weighed
- Heart is removed
- Neck organs, large airways, and lungs are removed
in one piece - Liver is removed and sliced
- Digestive tract removed
- then renal/sex organs removed
- Any suspect organ is inspected closely
60Autopsies Method
- Organs returned to cavity or cremated
- Body sewn up, baseball stitch
- Head more carefully sewn
- Body washed and forwarded as requested by family