Unit 8 : Death Investigation

distant gunshot wound

-lacks smoke and powder effects -range is normally indetermined -comprised of clean, circular skin defect and lacerated rim around the whole (bullet spinning) -diameter of skin defect is some indication of diameter of bullet, bit not always reliable due to differences o diameter of common bullets.

second degree burn

A burn marked by pain, blistering, and superficial destruction of the epidermis and the dermis.

3600

AC produces ________ quivers per minute.

mechanisms of death

a biochemical or physiologic abnormality produced by the cause of death that is incompatible with life. the events that follow the initial cause of death until you die. if someone is shot, the cause is gunshot and the mechanism is bleeding out. ex: exsanguination, internal hemorrhage, asphyxiation, cardiovascular failure, organ failure, anaphylaxia (allergic reaction).

hematoma

a blood tumor. blunt trauma to head will often produce a goose egg.

third degree burn

a burn involving all layers of the skin; characterized by the destruction of the epidermis and dermis, with damage or destruction of subcutaneous tissue.

chemical burn

a burn to skin caused by the interaction with harmful chemicals. chemical burns dissolve and erode the skin. the skin often appears as though it has melted off. there is no charring of the skin.

smooth bored weapon

a gun that does not have any grooves in the barrel. ex : shotguns and antique weapons.

rifled weapon

a gun that has spiral grooves inside the barrel, that make the bullet spin and is therefore more accurate and has longer range. most firearm deaths are caused by these weapons. ex : rifles and handguns.

puncture

a small hole made by a sharp object.

depressant

alcohol is a _________________ - it slows reactions and communications from the brain and spinal cord neurons. alcohol poisoning is the result of a failure of the CNS. person under the influence of alcohol breaths slower and slower until lack of oxygen causes death.

.3

around ____ gram percent of blood alcohol, person goes into a coma.

drug chemical trauma

barbituates, diazepams, and opiates produce deaths in same manner as death from alcohol. cocaine is a stimulant and high doses can cause seizures, extremely high body temperatures, and uncontrolled quivering of heart. marijuana is the only exception because it has never produced an overdose death.

thermal burns

burns caused by contact with open flames, hot liquids or surfaces, or other sources of high heat the skin chars when it is burned and is slightly browned or blackened.

blunt force trauma

can result from car accidents. generally, with exception of gunshot wounds, homicidal blunt force trauma in an adult requires lethal head injury - injuries to other areas rarely produce death. in children, head injuries are most common, however, chest and abdominal trauma with lacerations to spleen, liver, and heart are seen.

firearm injuries

cause blunt force trauma. classified by their projectiles: -gunpowder -smokeless gunpowder - nitrocellulose most common in suicides and homicides. injuries produced are result of velocity. the extent of the injury increases as the square of the velocity increases times the mass of the projectile. gunshot wounds can be classified as either penetrating or perforating. gunshot exit wounds are typically lacerated but not always. they are larger than the entrance wound. large lacerations are characteristic of head contact wounds. explosion of the head and evacuation of the brain may occur as a result of gunshots that produce large amounts of gas.

algor mortis

cooling of the body after death, and assumes ambient temperature is lower than body temperature. (98.4 - core body temperature)/1.5 = the number of hours from death. the equation varies depending on the type and layers of clothing, location (inside/outside), if the body was wet, humidity, etc.

stippling

created by unburned gunpowder on skin around hole produced by bullet. handgun creates this when help .5 centimeters to 1 meter away from skin.

penetrating

creates and entrance wound but not an exit wound - projectile must be recovered from the body to confirm this.

perforating

creates both an entrance and an exit wound - no projectile is recovered from the body.

low voltage AC

current (under 1000 volts) crosses the heart and ventricular fibrillation is experienced (nonpropulsive quivering of heart) that leads to nonresusibility within minutes.

exsanguination

death after a significant loss of blood - a major artery or the heart is damaged and blood loss occurs, and can occur in either sharp or blunt for trauma.

natural

death by no illegal/criminal means. usually chronic bit not always expected.

suicide

death by one's own hand or design. criminal: botched, assisted (euthanasia). noncriminal: kill yourself on purpose or accidentally.

homicide

death by the hand of another human. intent and planning determine severity in court.

drowning

death from asphyxiation die to immersion in water or other liquid. water enters stomach, then coughing and reflex inhalation cause water to enter smaller air passages of lungs. notable differences in conscious or unconscious victims. excitation phase of drowning may not be seen as prevalently in unconscious person due to the fact an unconscious person cannot become excited (aka water in lungs or not).

co

deaths due to ____ may be accidental, suicidal, or homicidal. ____ kills by asphyxiation - binds to hemaglobin 300 time more than oxygen and cuts off oxygen to the brain. blocks the oxygen from entering the hemaglobin. no energy required, just diffusion. people that die with a 1-2% co level in fires is evidence that they died or were not breathing when the fire started.

manner of death

determined by the medical examiner. the fashion in which the cause of death came to be. there are four main manners of death: natural, accidental, suicide, and homicide.

liver mortis

discoloration of body from settling of red blood cells after blood stops circulating, aka lividity. in light skin people, lividity may be seen an hour after death. in dark skinned people, lividity may not be able to be seen. substantial blood loss may result in little to no lividity. it begins 20 minutes to 3 hours after death and is darkest after 12 hours. turns purple after 24 hours. it will fade as decomposition sets in.

cause of death

disease or injury that initiated the lethal chain of events that led to death. the incident that started the domino effect. ex: gunshot wound, trauma, disease, etc.

50

ethyl alcohol (ethanol), an active ingredient in beer, wine, and liquor, is a contributing factor in ____% of traumatic deaths.

thermal trauma

exposure to excessive heat or cold may produce death. exposure to either cause breakdown of body mechanisms that maintain body temperatures around 37 degrees celcius. ability to maintain homeostasis declines with age.

close range gun shot

gas is projected from the barrel only a few inches and creates near-contact wounds - which creates blackening of skin. there will also be a significant amount of stippling. skin will show lacerations and the wound will not be clean cut at all.

cyanide

generally available as sodium/potassium salt or a vapor. smells like burnt/roasted almonds. up to 50% of the population can't smell cyanide (gene). forensic pathologists should be able to smell cyanide, especially in cases of suspected suicide.

300

heart normally produces _____ quivers per minute.

blunt force

injuries caused by blunt instruments. produces lacerations. ex : rocks, bricks, stones, etc. creates significant damage.

sharp force

injuries caused by sharp implements. produces incised and stab wounds. ex : wounds caused by knives, axes, swords, etc. has more depth than any other dimension.

incision

injury made by a sharp instrument and characterized by lack of surface abrasion and absence of bridging vessels, nerves, and smooth margins. do not make bruises.

laceration

injury produced by a blunt instrument; characterized by surface abrasion, bridging vessels, and nerves with irregular margins. red, torn, irregular shape and associated with bruises.

2nd degree murder

intentionally killing someone but without preplanning.

asphyxia

interruption of oxygenation to brain. may be caused by manual or ligature strangulation.

malfeasance

misconduct or wrongdoing, especially by a public official. doing the wrong thing with bad intent.

3rd degree murder

more commonly called manslaughter; an accident. no preplanning or intent.

1st degree murder

murder with intent and planning.

accidental

noncriminal: death with no intent or liability. fall in the shower and die, crash into a tree, etc. criminal: negligence. caretaker gives wrong dose of medicine accidentally. includes all types of feasences.

defense wounds

nonfatal wounds- cuts on the hands, arms, and legs- incurred by victims as they attempt to ward off attackers; indicative of murder. defending yourself is a natural instinct that is very hard to resist.

mechanical trauma

occurs when the force applied to a tissue exceeds the mechanical or tensile strength of that tissue. types include sharp and blunt force.

first degree burn

only epidermis is damaged. a mild burn characterized by heat, pain, and reddening of the burned surface but not exhibiting blistering or charring of tissues.

electrical trauma

passage of electricity through a person may cause death by a number of different mechanisms - low voltage, high voltage, direction is crosses the heart. is the current moves from head to toe or toe to head, you will be fine, it will only increase your heart rate. if current flows left to right, right to left, or at an angle, it will damage your heart and you will die.

chemical trauma

refers to injury caused by a chemical, such as alcohol or cyanide.

poration

result of flow of current through tissues which creates holes in cell membranes. creates devastating loss of limbs in person exposed to high voltage.

electric burn

results from passage of electrical current. these types of burns are very localized and can also experience charring. they are also deeper than other burns.

contusion

scientific word for bruise. accumulation of blood in tissue outside the blood vessels - most commonly caused by blunt force trauma. pattern of object may be transferred to person who is struck.

double edge

sharp on more than one side. makes a diamond shape wound. ex : butterfly, switch-blade, military knives.

rigor mortis

stiffness of the body that sets in several hours after death. results from a chemical reaction with glycogen. usually sets in about 4 hours after death and is fully set at 12 hours. it passes 48-60 hours after death. exceptions include electric shock and intense physical exertion before death (can be cut to 1 hour or less).

mid range gun shot

stippling will be present in varying amounts. there will be no burns from the gas. the wound will be a little more clean cut than the close range.

nonfeasance

the failure to act when one should

misfeasance

the improper performance of an otherwise proper or lawful act. doing the wrong thing with good intent.

hypothermia

too cold. death common in individuals that are intoxicated by alcohol - alcohol increases loss of body heat and reduces appreciation of the cold.

hyperthermia

too hot. heat related illness which can cause death. thermal burns caused by temperatures above 65 degrees celcius (140 degrees F) will produce burns upon contact. people that die from fires most commonly die from smoke and co inhalation and pass out before they die. if they do not pass out, the lungs will be scarred because the victim inhales the flames.

manual strangulation

use of the hands in strangulation. typically fractures the cornu of the thyroid cartilage. even more common, hemorage of muscles in neck. leaves finger and hand impressions.

high voltage

very powerful electric current. causes poration and electrical current burns a person in a fraction of a second.

single edge

weapon that is sharp on only one side. one side of the wound in pointed while the other side is rounded or flat. ex : butcher, steak, hunting knives.

yawing

when a bullet enters the body sideways. does not normally occur but can when bullet passes through a medium thicker than air.

ligature strangulation

whether by hanging or garroting (cord or wire). generally results in finding furrows (impressions) in neck from object.

contact gunshot

wound make when gun is shot while pressed against the body. burns an impression of the gun on the skin. no stippling. nowhere for the powder and gases to go so they go inside the body.