Section 1
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temperate climate lasts for 2-3 days; tropical climate 24-48 hours in winter
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Date created
Mar 1, 2020
Cards (107)
Section 1
(50 cards)
temperate climate lasts for 2-3 days; tropical climate 24-48 hours in winter
environmental effects on rigor
occurs when lividity is not fixed, the skin does have a red and purple appearance but when pressure is applied, the blood is able to be moved around
blanching liver mortis
"coolness of death"; postmortem cooling; need to check inner core temperature for true measurement (underarms and groin); thinner people cool faster; affected by ambient temperature/environment
Algor mortis
important for asphyxia, separate removal and examination; layered look at the structures in the neck to rule out strangulation
Neck dissection
hypothermia and cold storage; debilitated, frail, or very small kids; carbon monoxide poisoning
factors slowing rigor
Mummification
starts 1-2 hours after death; blanching up to 8-12 hours; becomes fixed after 12 hours or so
timeline of liver mortis
maggot activity
cadaveric spasm
enzyme driven process; starts 3-4 hours after death and continues for 2-3 days; first seen in enzyme rich organs; softening and liquefying of the body tissues
autolysis
determine cause and manner of death; identify the deceased; determine time of death and injury; collect evidence from body; document injuries or lack of; decide how the injuries occurred; document natural disease; provide expert testimony
ME responsibilties and duties
action of bacterial enzymes on tissue components- carbs/fats/proteins; bacterial growth is favorable in warm and moist conditions; clostridium species
bacteria in decomposition
skeletalization
bacteria driven; autolysis is a part of; dependent on environment temperatures; slower in children or thin individuals
putrefaction
the maximum cavity created by the energy of the bullet is a larger point than the linear path of the bullet. the shearing forces that stretch and tear the tissues when the bullet hits and then collapses as the bullet continues to slow
temporary cavities
exercise; seizures/convulsions; electrocution; hyperthermia/fever; hot environment; strychnine poisoning
factors accelerating rigor
the white splotches seen on this man's face show that he was on his face while lividity was setting in and there was something pressing against his face; suggesting that he not suffocated
primary relaxation/flaccidity; rigor mortis/cadaveric rigidity; secondary relaxation
changes in the muscles
can certify that the person is dead and sign a death certificate
Coroner responsibilities
usually a round to oval defect; punch out defect (with the central piece missing); marginal abrasion ring or collar; soot and/or stippling; sometimes a muzzle imprint
entrance wounds
very rough estimates, lots affect the timeline; onset 1-2 hours after death; develops to maximum over 12 hours; around the max between 12-24 hours; then passes to absent
duration of rigor
barrel is smooth because the rifling would spread the shot patten too soon
shotgun barrel
understand and document medial disease; reveal undiagnosed or misdiagnosed illness; collect legal evidence; ease the stress of the unknown; procure tissue for lab testing; investigate public health emergencies
Reasons for Autopsy
skin marbling
"stiffness of death"; post mortem stiffening; not related to nerve activity; first appears in involuntary muscles; due to actin-myosin filament linkages which are ATP dependent
Rigor mortis
small, black spots that result from the breakdown of blood vessels, not to be confused with trauma to small vessels
Tardieu spots
soft tissues expanding, bloating due to bacterial activity and gas buildup; marbling of the skin as a result of blood vessel breakdown; skin blisters start to form and fill with fluid; mummification
Mild decomposition
if the body position does not make sense, could be evidence hat the body was moved
inappropriate rigor
blush red but variation is wide
usual color of lividity
cadaveric spasm= hands abruptly clenched, usually preceded by excitement or tension; pes anserins= like goosebumps where the hair in the follicles stand up; semen at the tip of the penis from seminal vesicles
rigor mimics:
type of bullet where the pin hits the center of the casing bottom to ignite the primer
centerfire
starts immediately after death with generalized relaxation of muscle tone; drop of lower jaw; eyeballs lose their tension; pupils are dilated; joints are flabby; smooth muscle relaxation
primary relaxation
does not eject the bullet cases, the case is kept in the revolving chamber
Revolver
the size of bullet entrance hole is NOT the diameter of the bullet. skin is stretchy. permanent skin defect is usually smaller than the bullet caliber
wound size
revolver and semi-automatic
Handgun types
decomposition/putrefaction; adipocere formation/saponification; mummification
late signs of death
last stage in the resolution of the body from the organic to the inorganic state; bacteria flourish on now available materials
decomposition
"color of death"; blood vessels are dilated so the blood in them fall to the lowest point of gravity; begins to develop 1-3 hours after death and becomes fixed by 10-12 hours; once fixed, will not move anymore when the body is moved
Livor mortis
cycling of firing and the casing is ejected from the chamber
Semi-automatic
greenish discoloration of skin over lower abdomen and to the flanks after death 18-24 hours; greenish to black discoloration (sulphmethahemoglobin formed by H2S due to microorganisms in large intestine); appears early in the summer and later in the winter
color of putrefaction
brusing = crushing of tissues, bleeding in deeper tissues; lividity = gravity dependent, blood on the skin surface only
bruising vs lividity
skeletalization; maggot activity
Severe decomposition
Adipocere
type of bullet where the pin hits the outside rim to ignite the primer
rimfire
blush red= normal; cherry red= cold storage, carbon monoxide poisoning, cyanide poisoning; brown = sodium chlorate; green = H2S gas
other colors of lividity
pretty severe green and black discoloration of the skin; bloating of the extremities (face and hands); tongue becomes bloated and sticks out of the mouth due to bacterial activity; "degloving" of the hands and feet; skin blisters have popped and the skill sloughs off
Moderate decomposition
after the main organs removed; incision made behind one ear, over top of head, and behind the other; Stryker saw used to removed skull cap; brain stem cut and brain is then lifted out of skull to be weighed and examined
Brain removal
external exam; Y cut and removal of main cavity organs; brain removal; neck dissection; and autopsy report
Steps of Autopsy
bullet/shot; soot; gunpowder particles; gases, flame; shotcup or wadding
what comes out of the barrel?
the barrel is grooved, which puts a spiral spin on the bullet for greater accuracy
rifle or handgun barrel
Section 2
(50 cards)
external exam; internal exam; photograph external and internal injuries; toxicological exam; microscopic exam; official autopsy report
what does an autopsy entail?
can tell you the direction of the bullet; tags and tears
usually performed in hospital say pathologists or the attending physician to determine the cause of death for research and study purposes: needs family consent
medial autopsy
forensic and medical
types of autopsy
gases and soot will tear the skin first to take the path of least resistance, will result in stellate tears. the bone may push back due to the forces of the gases. the bullet will bevel on flat bone, on the inside of entrance wound and outside of exit wound. Contact wounds may leave muzzle imprint, may see soot stain on the bone.
entrance wounds on skull
stab wounds
skin with central defect. radiating lacerations (tight contact), searing or margins, marginal abrasion, muzzle imprint, soot found on clothing, skin surface and within the wound. gunpowder particles on the skin. pink-red discoloration of the tissue. bone and dura mater will show soot. bone with inward beveling. barrel of gun pattern abrasion, hands back spatter and/or tissue. high velocity wriggles and shotgun contact wounds freq. cause massive destruction.
contact wounds
changes in the eye, changes in the skin, cooling of the body/algor mortis, liver mortis, rigor mortis
changes to evaluate
contact, intermediate, distant/indeterminate
range of fire
cut wounds
super high velocity, shreds internal tissue. entrance wound may have "micro" radiating lacerations in distant range wound from high velocity rifles. typically have marked destruction of internal organs due to high velocity and energy of bullet. bullet is obliterated and won't usually exit as a pretty bullet. internal organs are just pulpified.
rifle wounds
fingerprints, DNA, dental, unique radiological findings, medical devices, etc
definitive identification
permanent cessation of cardiac or respiratory function
definition of death
HOW the cause of death came about; natural, homicide, suicide, accident, or undetermined
manner of death
instantaneous death, sudden; ex. impact abrasions or cardiovascular disease related
sudden, unexpected natural death
when a physician or medically trained professional determines that life functions have ceased
when is one declared dead?
dense marginal ring of soot on the skin surrounding the entrance gunshot wound without stippling. can be clumps of dense collections of soot. shape of soot clump can also tell is the fun was held at an angle
near contact wounds
abraded margins, skin reinforced or "shored" by a firm surface; bullet may not completely exit the body. ex. if your back is against a wall, the bullet tries to exit, and your skin bounces. not to be confused with an entrance wound
"shored" exit wounds
injury extends to subcutaneous tissue
tangential wound
can be determined when the ME is really unable to make a decision between different manners of death
undetermined
death by natural causes, majority caused by old age or long standing disease
natural death
often caused by mistake or in a freak occurrence; not planned but can be explained by surrounding circumstances
accidental death
elongated abrasion without perforation of skin
graze
beyond that range of the gunpowder reaching the skin. marginal abrasion collar. no soot, gunpowder, or stippling. distance usually greater than a few feet-can't tell distance.
distant range gunshot wounds
length of skin, depth of track, ends and edges (sharp/blunt/undetermined), associated abrasion and/or contusions, pattern?
sharp wound characteristics
occurs in partially opened eyes and leads to drying artifacts; brownish-black line that can be mistaken for bruising; occurs due to air exposure when the eye lids are open
Tache Noir
examiner spends as much time on the external surface as they do on the internal surface because that's where the evidence: does not need family consent
forensic autopsy
result of one taking their own life
suicide
measured, weighed, and cleaned; photographed; physical evidence collected oof the body; document basic features (hair color etc), and identifying features; document postmortem changes; examine for wounds or natural diseases (surgical scars etc)
autopsy: external exam
usually single entrance wound up to about 4-5 feet. may see scalloped edges when it gets slightly further away. general mass but some satelliting of individual pellets
close/contact shotgun wounds
soft tissues get ripped apart by the bullet, especially the soft organs. the liver can be torn with a hole following the path of the bullet, but whole organ is still intact.
internal gunshot wounds
saw used to cute and remove a wedge shape portion of skull so that the brain can be removed
Stryker Saw
legal document; description of findings; opinion of ME based on all available information at the time
autopsy report
typically larger and more irregular, punch out (so you can kind of fit the skin back together), no abrasions rim/collar
Exit Wounds
result of one person killing another
homicide
usually seen in X-rays for high velocity rifles
lead snowstorm
the fact, what the person died of
cause of death
state or process of rotting; starts the moment a person dies due to lack of oxygenated blood to cells/tissues
decomposition
presumptive and definitive
types of autopsy identification
often the site of earliest changes; corneas can get filmy within minutes (depends on if the lids are closed or not); tache noir; eyeballs will collapse and absence of ocular build approx. 3-4 days after death
early ocular changes
to ascertain if alcohol, drugs, and/or medications are in the decedent's system that the time of death; can confirm or refute overdose or poisoning; to confirm presence/levels of therapeutic drugs
why take toxicology?
circumstantial, visual, matching tattoos and other distinctive marks
presumptive identification
pattern of elastic fibers in the dermis of the skin which is approx. the same from individual to individual. the elasticity or laxness of the skin can increase or decrease the dimensions of the wound in the skin. lines of tension or relaxation
Langer's lines
normally moist areas dry. open prolonged exposure to air after death; scrotum one of the most frequent areas of this early change
postmortem scrotal drying
hard, loose, angled, incomplete
contact wound types
"Y" cut made; external soft tissues reflected and Y opened up; chest plate removed and one by one organs removed
autopsy: internal exam
loss of its translucency; loos of. elasticity; wounds will not bleed if inflicted after death; wounds can look dry and shape can be affected; based on the drying of the skin and other decompositional factors
changes in the skin
soot and gunpowder particles on the skin. gunpowder stippling. basically anytime there are gunpowder particles hitting the skin. as distance increases, there will be less soot and wider/less dense pattern stippling.
intermediate wounds
defines close range fire, burned soot on the skin, small abrasions producer by gunpowder striking the skin, typically from 1/2 inch to 1-2 feel for most handguns. little bleeding caused by the burning of the gunpowder. Sometimes other things can mimic stippling from the gunpowder (like fragmentation of bullet or glass, petechiae)
Stippling
wound track deep than length on skin edges usually w/o abrasion or contusion. forced into tissue with thrusting manner. cuts rather than tears. depth of wound not equal to length of blade.
stab wounds
Section 3
(7 cards)