Death Investigation Flashcards
System of Death Investigation
English speaking countries- coroner is the gov. agent charged with responsibility for death investigations
When the US was formed, death investigation was considered a local, governmental, or county function was created and no provision was made in the US Constitution for a coroner
Federal gov. had no death investigation operations, except DC until the creation of Armed Forces ME’s Office in the Armed Forces Institute of Pathology in the 1990s.
Each state enacted coroner’s laws and coroners are most likely elected county officials.
Medical examiner system
1877, Mass. Adopted by NYC, Baltimore, and Richmond around WWI, DC switched to ME system in 1970
Legislature passed a statute that replaced coroners with medical examiners which are required to be licensed to practice medicine
Change was set into motion by local scandals arising from deaths improperly investigated by coroners
Several NYC deaths caused by incompetent administration of anesthesia during surgery.
Coroner system has become antiquated and is no longer considered the best structure for systematic scientific death investigation
Charles Norris (1867-1935)
Served as NYC’s 1st Chief Medical Examiner (1918-1935)
Tenure spanned explosion of Wall Street and implosion of the stock market, Prohibition, and Gang Warfare
He pioneered the structure of medical examiner’s offices in the US
Forensic Pathology
Physicians specialized in the diagnosis of disease
Subspecialized in area between law and science that emphasizes the determination of cause of death
Cause of Death
disease or injury that led to death; underlying cause
Manner of Death
fashion in which the COD came to be
1. Natural
2. Accidental
3. Homicidal
4. Suicidal
Undetermined/ Unclassified
Algor mortis
cooling
cooling of the body that occurs after death
Algor means “coldness”
Mortis means “of death”
Rigor mortis
stiffening of muscles that occurs following death
Stiffening of muscles that occurs following death
Early onset – 0.5 hours
Fully fixed – 12 to 24 hours
Caused when glycogen in muscles is used up
Disappears during the period from 24 to 36 hours after death
Livor mortis
pooling of blood
discoloration from the settling of RBCs after the blood stops circulating
onset 30 mins. to 2 hrs
lividity becomes fixed ~ 12 hours after death
Death investigation tools
Sudden death – occurs w/in a few hours of the onset of symptoms or death w/o any symptoms
Example- diagnosis of cardiovascular disease = death not unexpected
Is the death sudden?
is the death unexpected? check medical records
forensic pathologists do not recognize a statute of limitations for fatal injuries
examine the scene of the death
Autopsy v. Necropsy
autopsy: to look at oneself
necropsy: surgical examination of a dead body
Describe an inframammary incision
color bones in a Y shape heading down the abdomen to the genitalia
What happens during an autopsy?
postmortem dissection is mandatory if a death is properly within the jurisdiction of the coroner or medical examiner, and the cause of death is not determinable without dissection.
Examine brain- incision from behind one ear to behind the other – scalp peeled upward and backward; circular cut of skull- remove skull cap
Brain- either dissected immediately or put in formaldehyde to fix the tissue for better examination and dissection.
Fixation- chemical process that causes proteins to harden; it preserves the tissue and prevents further decomp.
Suspected child abuse cases- occasionally- posterior neck dissection to check for any injury to the muscles, ligaments or spinal cord. In cases of suspected child abuse, incisions may be made to show that bruises that may not show externally.
Samples- toxicology and DNA exams (urine, blood, bile)
DNA typically a blood spot card and head hairs (must get roots)
Tissues- typically preserved in paraffin blocks, mounted on glass slides (often by histologists)
Types of traumatic death
Mechanical
Thermal
Chemical
Electrical
mechanical trauma
Sharp force- incised wounds like stabbings
most common COD is when the brain has been significantly injured or the heart has been lacerated
blunt force- car accident
Firearms are most common:
Extent of the injury produced by a firearm projectile increases as the square velocity increases
High velocity – high-powered hunting rifles; military rifles; only handgun capable of this (on the lower end of high) is the .44 magnum
penetrating
Penetrating – entrance but no exit; projectile must be recovered
perforating
Perforating- exit and entrance
hematoma
Hematoma- hema “blood” and toma “tumor”- tumor of blood caused by leakage from damaged blood vessels; forms a blood-filled space
contusion
bruise caused by bleeding beneath the skin
chemical trauma
Result from the use of drugs and poisons
Drugs of Abuse
Depressants
Stimulants
Carbon Monoxide
Cyanide
Ethanol is most common contributory drug
thermal trauma
hypothermia and hyperthermia
Both cause death via breakdown in the normal mechanisms that maintain body temperature (37C or 98.6F)
Diagnosis requires the absence of other causes of death coupled with a history of exposure to an environment that can cause it.
electrical trauma
Circuit of alternating current (AC) at low voltages(<1000) crosses the heart = ventricular fibrillation (quivering that leads to non-resuscitability within minutes; AC acts like a pacemaker; AC in the US alternates from + to – 3600 times/min…. Produced ~300 quivers/minute in the heart (as fast as the heart can beat); electrical burns are not typical
High voltage- v-fib less likely because the amount of current becomes defibrillatory; forces the heart into tetany (sustained contraction only broken when the current is broken). Heart will start in normal rhythm again but electrical burn can occur within a fraction of a second. The flow of current also causes holes in the membranes of the cells (poration); causes devastating loss of limbs
asphyxias/ why special
Where does asphyxial death fall? Caused by interference of oxygenation of the brain. Can occur from mechanical (strangulation), chemical (cyanide poisoning), electrical (low-voltage electrocution)
mechanism of death
biochemical or physiologic abnormality produced by COD
shored exit wound
has the appearance of a ‘false’ abrasion collar. This false abrasion collar results when epithelium is forced outward and makes contact or is slapped against a supporting structure, i.e. floor, wall or furniture.
