Forensics Flashcards
How does the proximate cause of death differ from the mechanism (immediate cause) of death?
proximate cause of death is the true cause of death; mechanism of death is the final pathophysiologic event; the proximate cause is what was primarily responsible for the final pathophysiologic even (aka the mechanism)
Is ventricular fibrillation/ cardiac arrest/ congestive heart failure/ or MI a proximate cause of death or the pathophysiologic events (mechanism of death)?
final pathophysiologic events (mechanisms of death)
what is the most common proximate (cause) of death in the US related to the final pathophysiologic events like ventricular fibrillation/ cardiac arrest/ MI?
atherosclerotic cardiovascular disease (ASCVD)
What is a manner of death and how does it differ from the cause of death?
the manner of death is an opinion based upon everything known about the history of the deceased the circumstances surrounding the death and all elements of the autopsy; cause of death is generally ascertained by scientific means
What are the differ manners of death?
NASHU; natural, accident, suicide, homicide, and undetermined
Why is homicide not the same thing as murder?
homicide is when the life of someone is taken by a person or entity; murder is a legal charge; therefore the category of homicide would include legal execution of an individual by a state or nation
Why does accurate death certification in the US serve the public interest?
it is vital in ascertaining the magnitude/epidemiology of diseases/disorders of most concern
Who can certify a natural death?
any licensed physician
Who can certify other manners of death besides natural? (including undetermined)?
medical examiner physicians or in certain jurisdictions, coroners or justices of the peace
Who can certify death if it appears to be natural but there is doubt or foul play must be ruled out?
evaluation of the decedent falls within the jurisdiction of a medical examiner (or in some jurisdictions a coroner or justices of the peace (JPs)
What is rigor mortis?
stiffening of muscle groups after death
when does rigor mortis tend to occur?
within hours, but manifestations are modified by ambient and/or fluctuating temperatures
what is algor mortis?
cooling of the body after death; possibly relevant and calculable based upon a steady ambient temperature; rarely can be done with great precision
what is livor mortis?
movement of circulating blood to dependent areas of the body
what is livor mortis useful for?
can be useful in ascertaining movement of a body within or from the place of death
What are the 3 major forms of body decomposition?
putrefactive, mummification, and adipocere formation
what is putrefactive body decomposition?
typically occurs in most temperature settings; increasing features of discoloration, tissue softening/liquefaction, gas production and body bloating
What is mummification?
occurs in very dry arid climate settings
what is adipocere formation?
death and immersion within a body of water with saponification of epidermal surfaces
What is the accuracy like of “time of death” based on elements of the major forms of body cooling/changes and forms of body decomposition?
time of death based on these factors is generally very much an approximation
How does a forensic autopsy and a hospital autopsy differ in intent?
the goal of the forensic autopsy is to render a (proximate) cause and manner of death via a careful medicolegal investigation employed to obtain the acquisition of justice in the service of the public
when is a forensic autopsy usually performed and what effect does this have on the technical features?
in the setting of foul play/trauma; the external examination with careful documentation of wounds by photography/drawings and schematics plays a major role; in-situ documentation of projectiles and other objects with radiographs can be very important
What is the intent of a hospital autopsy?
evaluating death due to natural causes
how do the technical features of a hospital autopsy differ from a forensic autopsy?
while external examination should still be performed carefully, it is not a central focus as in forensic autopsy
What are the goals of hospital autopsy centered on?
upon documenting extent of (natural) disease or the existence of disease that may have contributed to death but was undiagnosed prior to a patient demise
How long is pathology residency?
at least 4 years
how long is a forensic pathology fellowship?
generally 1 year
Who does a ME have legal duty to?
an ME has no duty to families or next-of-kin of deceased individuals that fall under their jurisdiction; the duty of an ME is to the public he/she serves
What is rigor mortis?
stiffening of muscle groups after death
when does rigor mortis tend to occur?
within hours, but manifestations are modified by ambient and/or fluctuating temperatures
what is algor mortis?
cooling of the body after death; possibly relevant and calculable based upon a steady ambient temperature; rarely can be done with great precision
what is livor mortis?
movement of circulating blood to dependent areas of the body
what is livor mortis useful for?
can be useful in ascertaining movement of a body within or from the place of death
What are the 3 major forms of body decomposition?
putrefactive, mummification, and adipocere formation
what is putrefactive body decomposition?
typically occurs in most temperature settings; increasing features of discoloration, tissue softening/liquefaction, gas production and body bloating
What is mummification?
occurs in very dry arid climate settings
what is adipocere formation?
death and immersion within a body of water with saponification of epidermal surfaces
What is the accuracy like of “time of death” based on elements of the major forms of body cooling/changes and forms of body decomposition?
time of death based on these factors is generally very much an approximation
How does a forensic autopsy and a hospital autopsy differ in intent?
the goal of the forensic autopsy is to render a (proximate) cause and manner of death via a careful medicolegal investigation employed to obtain the acquisition of justice in the service of the public
when is a forensic autopsy usually performed and what effect does this have on the technical features?
in the setting of foul play/trauma; the external examination with careful documentation of wounds by photography/drawings and schematics plays a major role; in-situ documentation of projectiles and other objects with radiographs can be very important
What is the intent of a hospital autopsy?
evaluating death due to natural causes
how do the technical features of a hospital autopsy differ from a forensic autopsy?
while external examination should still be performed carefully, it is not a central focus as in forensic autopsy
What are the goals of hospital autopsy centered on?
upon documenting extent of (natural) disease or the existence of disease that may have contributed to death but was undiagnosed prior to a patient demise
How long is pathology residency?
at least 4 years
how long is a forensic pathology fellowship?
generally 1 year
Who does a ME have legal duty to?
an ME has no duty to families or next-of-kin of deceased individuals that fall under their jurisdiction; the duty of an ME is to the public he/she serves
What is an abrasion?
damage to overlying skin/epidermis
what is a laceration?
splitting of skin with hemorrhagic bridges in depths
What is a contusion?
intact skin with hemorrhage in dermis and below
What injuries are caused by blunt force?
lacerations are always caused by blunt force; contusions are often due to blunt force; abrasions are often due to blunt force
What is a well established parameter of analysis with an appearance of yellow color associated with?
a contusion over 18 hours old
How does a laceration differ from an incise wound?
incise wounds are generally due to edged instruments (razors, knives); incise wounds are deeper than they are wide; lacerations are wider than they are deep; lacerations have hemorrhagic bridges in the depths; incise wounds are without bridging in the depths
What are potential comorbid factors that might enhance, exacerbate, or complicate wounding?
chronic renal disease (often due to diabetes and or hypertension), advanced liver disease, may be associated with more bleeding at injury sites
What are different types of handguns?
revolvers and semiautomatics
what type of velocity are handguns?
low velocity
what type of bullets are handguns loaded with?
small caliber bullets
what is a common handgun used by civilian concealed carry permit holders and police?
a hollow-point round
What are hollow point rounds designed to do?
hit an individual and “mushroom over the base” when they strike tissue
what is the effect of a hollow-point round?
the effect is to slow the round tumbling
what is the purpose of a hollow-point round?
the deformed bullet will remain in the individual rather than passing through and injuring another; induces more tissue damage though
how are gunshot wounds of entry characterized?
by marginal abrasion
if there is an exit wound of a small caliber bullet, what is it like?
it often has a more stellate configuration and may be somewhat larger than the entry
what do modern handguns have?
rifling (grooves cut into the lining metal of the barrel)
what is the purpose of rifling on modern handguns?
this adds to weapon accuracy and imparts lans and grooves to rounds fired through the barrels
What do “machine pistols” fire?
handgun ammunition
what are civilian versions of machine pistols?
semiautomatic
what are law enforcement versions of machine pistols?
fully automatic
What type of velocity are long guns (rifles) considered to be?
high velocity
what are long guns (rifles) loaded with?
fully jacketed bullets
what do GSWs of entry of long guns look like?
marginal abrasions
what do GSWs of exits of long guns (rifles) look like?
more stellate and considerably larger than the entries
Do long guns have rifling?
yes in the barrels; for accuracy at longer ranges
What are shotguns (smoothbores)?
the rounds loaded into a shotgun typically are shells that contain pellets of varying sizes
What does firing a shotgun induce?
a spray of pellets
what is dispersion of the pellets controlled by?
a choke structure
What is the effect of lesser of a choke?
it allows for greater dispersion of the shot mass
what is a law regarding shotguns?
in the US, the length of a shotgun barrel cannot be too short by law
why are too short of barrels illegal?
it has virtually no choke and a wide dispersion of pellets at a short range
What are three broad categories of firearms?
handguns, long guns, and smoothbore (shotguns)
What are the different types of rifles?
bolt action and magazine type
What is associated with devastating close-range injuries?
it is possible to load a shotgun with so-called “slugs”; such large projectiles are associated with devastating close-range injuries
What does range refer to?
refers to the distance of the end of the gun barrel from the entry wound on the individual
What does an accurate determination of range depend on?
having the same ammunition and same weapon to fire and recapitulate findings on the decedent
What does an adult skull have?
an outer table and an inner table separated by spongy bone known as the diploe
describe the entry wound of GSWs of the head as they typically appear in the inner and outer tables of the cranium?
Entry wound: outer table is sharply circumcised; inner table is beveled
describe the exit wound of GSWs of the head as they typically appear in the inner and outer tables of the cranium?
Exit wound: inner table to sharply circumcised; outer table is beveled
