ANTH 105 EXAM 3

Exam 3 and final material

Who can pronounce death?

M.E. - forensic pathologist

Coroner - elected or appointed

Doctor

First US Coroner

Maryland 1637

Training for coroner

no formal medical training required

First US M.E.

1890 Baltimore Maryland appointed 2 doctors

M.E training

Physicians with specialized training in forensic pathology

NAS recommendations for coroners and M.E.

Get rid of coroner system, replace coroner with M.E. in every jurisdiction

Why is the coroner system not gone yet?

political reasons, can be used as a political stepping stone, used in the south to cover up lynching

Forensic pathologist

a pathologist who studies disease and trauma that lead to death = M.E.

Pathologist

doctor who studies and diagnoses diseases in humans. = M.E.

Autopsy

Greek for seeing with ones own eyes , standard dissection of body to determine cause and manner of death

Hospital Autopsy

Did doctor make mistake

Medicolegal Autopsy

investigate sudden, unexpected, or suspicious deaths

External Autopsy

Older individual that lives alone, also draw blood

Authority to investigate deaths

from criminal violence, accident or suicide, sudden nature when otherwise in good health, unattended by a physician, custody of state/city, in a suspicious or unusual manner, family can request autopsy

Religion except from autopsy

Judaism, Islam = M.E. can override this, some jurisdictions try to respect religious practices

Death certificate

legally dead for voting, insurance, and tax purposes

Death investigation

Scene investigation, examination of the deceased, identification of the deceased, determine cause of death, manner of death, produce death certificate

Death

Irreversible cessation of circulatory. and respiratory function

Cause of Death

injury or disease responsible for the pathological and physiological disturbances that resulted in death (Medical reason for death)

Examples of cause of death

The final disease or injury causing the death

Natural causes of death

Heart disease, diabetes, cancer

Asphyxiation

interruption of oxygenation of the brain. ex: strangulation or positional

Exsanguination

death by loss of blood

Manner of death

the circumstances under which the cause of death occured

Manner of death classifications

natural or unnatural

Manner of death: natural

natural disease, dies under care of doctor

Manner of death: unnatural

homicide, suicide, accident, undetermined, therapeutic complication

Manner of death: therapeutic complication

person dies during operation, normal complications that may occur during medical interventions

Manner of death: accidental

died by car crash/ accidental mistake

Manner of death: suicide

killing yourself

Manner of death: homocide

dying at the hands of another, can potentially be accidental,

Homicide

Not all homicides are murder

All murders are

homicides

Manner of death: undetermined

not enough evidence

Injury: Antemortem

sustained prior to death, may have healed or shown signs of healing

Injury: Perimortem

occurred at or near the time of death, no signs of healing

Injury: Postmortem

occurred after death, considered “modifications” from events such as carnivore gnawing/freeze or thaw/weathering

Mechanical Trauma

Applied force exceeds the strength of tissue (sharp force + blunt force)

Chemical trauma

damage and death resulting from the interaction of chemicals with the body

Gunshot Trauma

Gunshot wound, bone fractures

Thermal trauma

extreme heat or cold

Hypothermia

too cold

hyperthermia

too much heat

electrical trauma

injuries or death caused by electricity passing through the body

Decomposition is

variable/predictable

Decomposition is used to

predict how long someone has been dead for

Taphonomy

The laws of burial, greek: taphos = burial or grave + nomos = law

Generally human decomposition follows…

a set of processes

Post Mortem Interval

Time since death, assessing time since death

Post Mortem Interval: What factors caused

the destruction of remains, the dispersion of remains, are there modifications to bone, are the bones human or non human

Forensic Taphonomy

Time and circumstances of death

Rodents prefer when bones are

dry

Decomposition Definition

systematic continuum of tissue breakdown

Two Significant decomposition processes

External and internal

external decomposition

soft tissue decomposition or desiccation

Internal decomposition

cell death and prolification

Stages of decomposition

Fresh, bloat , active decay, advanced decay, dry remains/skeletonized

Estimated PMI on

degree hours, summer vs. winter temperatures, accumulated degree of hours

External (Extrinsic) decomposition processes

environment, animal activity

Internal (Intrinsic) decomposition proccesses

autolysis, gut bacteria, green belly

Initial phases of fresh

Livor,algor, and rigor mortis

Livor-mortis

blood settles, discoloration, well formed in 3-4 hours , fixed 6-8 hours, highly variable, important to determine if body has been moved

algor mortis

body cooling, cold death, determined by liver or rectal temperature, highly affected by location/room temperature, drop about 2 degrees per hour, does not start immediately following death, drops to equal room temp, influenced by body size

rigor mortis

stiff muscles, the period of time that a body goes through a state of rigidity, usually starts 2-4 hours post death, peaks then subsides, 12 hours for whole body to go rigid, 2-36 hours body can show rigor

rigor mortis starts…

at head and goes down to toes

Fresh stage - eyes

fluid in eyes become cloudy

bloat

putric faction begins, autolysis causes cells to self-digest and bacteria proliferates

bloat: bacteria

as bacteria feeds, they produce CO2, causing abdominal swelling/bloat

Active Decomposition

Putrefaction - bacterial activity leading to destruction of surrounding tissue

Active Decomposition - marbling

red—> darker red—> purple—> green, large scale discoloration

Active Decomposition - Degloving

skin slippage

Active Decomposition - bugs start

flies attracted within minutes, lay eggs in eyes/nose, once eggs hatch turn into maggots

Advanced decomposition - decay

intense and increased soft tissue decomposition

advanced decomposition

most of fluids have leaked out, decomposition island

advanced decomposition - purge

liquefaction

advanced decomposition- hair mat

hair slips off

advanced decomposition

skin cracking

The dry stage of decomposition - skeletonization

exposure of bone to outside environment

The dry stage of decomposition

longest lasting stage, eventual breakdown of skeletal material, commonly affected by taphonomic process

Decomposition Variation

The formation of “grave wax” due to hydrolysis of lipids (fat), typically occurs in moist/ colder environments, can co-occur with “typical” decomposition

Decomposition Environmental effects

temperatures, sunlight vs. shade, insect access, humidity

Additional influence on decomp

geography, seasonality

Individual variations - decomp

disease factors, trauma, age, size, ratio of muscle to fat tissue, medications

PMI is the time between

death and discovery of corpse

Isomorphe diagram

represents all the structural stages from hatching of eggs to eclosion phase

Isomegalem diagram

a chart that plots the size of larvae over time while accounting for environmental temperature less accurate than isomorphe graph

Forensic Entomology

study of insects and their arthropod relatives as applied to the legal system

Main application of forensic entomology

the determination of the minimum time since death

General areas for Forensic entomology

Urban - home infestations, Stored products pest - restaurants, medicolegal - criminal investigations

Medicolegal forensic entomology

criminal investigations

necrophagous

carrion feeding insects that typically infest human remains

Myiasis

infestation of live humans, ex. nursing homes

Entomotoxicology

drugs in insects feeding on humans, toxicology in insects = drugs in human being fed on by insects

Insect evidence is the most accurate method to estimate time of death up to…

72 hours

Post Mortem Interval

time since death

Insect activity can reveal

presence of drugs & toxins in the body, if body was moved from original location, if the presence of insects are not native to the area

Position of wound sites

can point out openings that are there other than typical eyes, mouth,ears

PMI can determine…

seasonality: temp, weather, humidity - development of insect

Development of insects

larval, weight, length, age - maggot eggs at 23 hours, blowfly at 143 hours

Diptera (flies)

four life stages: egg, larva (maggots), pupa, adult - show up within minutes of death