Midterm 2 Death Scene Investigation

Rigor mortis

The tightening of the muscles in the body due to an increase of lactic acid after death that starts simultaneously and is increased by heat and physical activity. (sets in 0-12 hrs, resolves in 24-36 hrs)

Livor Mortis/Lividity

Gravitational settling of the blood after death; usually maroon or purplish color to the skin (starts 30min-2 hours; becomes fixed in 8-12 hrs) and is effected by environment and climate (Ex: Red= cyanide, purple=heart failure)

Decompositional signs

bloating of body w/ skin slippage, green discoloration, marbling of skin, purge from orifices, disintegration of body, mummification, skeletonization

Abrasions

Scrapes

contusions

bruises, implies blunt force

lacerations

tears

Incised Wounds

more hemorrhage than lacerations

Defense wounds

on arms or legs can rebut claim of accident

Autopsy

A postmortem examination to determine the cause of death

Hospital autopsy

directed towards substantiating the accuracy of a clinical diagnosis or for other quality assurance reasons

Medicolegal (forensic) autopsy

Determines cause of death, collect evidence from the body, document findings, obtain evidence in identification

Steps of an autopsy

Photograph body and clothing, document cars, tattoos, injuries, notable marks, examine clothing, collect trace evidence, collect toxicology, microbiology specimens, external exam, x-rays, internal exam, package evidence, and collect fingerprints

Why is a positive identification important?

Ensures death certificate is issued to proper decedent, allows family to finalize financial affairs, and prevents fraud

How can we identify someone?

eyewitness, fingerprints, internal autopsy findings/medical appliances, dental records, DNA/genealogy, circumstances

What questions should a traffic death scene answer?

Was the person alive at the time of accident or was death due to natural event? What were the underlying contributing factors that may have cause the accident? If more that one death, who was the passenger and who was the driver?

Scene investigation of a traffic fatality

Weather, location, direction of travel, speed limit, estimated speed, roadway, skid marks, debris field, type of accident (front, side, rollover, rear impact, vs.), driver impairment, driver vs. passenger

Common traffic fatality injuries

Hinge skull fracture, aortic tears, liver/spleen lacerations, abrasions, road rash, pelvic fractures

Vitreous

gel-like substance in the eye that is useful for quantifying alcohol & verifying blood-alcohol level, electrolyte levels, & glucose levels

Rokitansky technique

block style that allows organs to be evaluated in relationship to their interconnections such as vasculature or ducts

Virchow technique

uses an organ-by-organ approach that uses the natural retraction of the body itself & allows the connections to be viewed for the majority of cases