ABIO 175 Exam 2

Death Investigation

Primarily during suspicious or questionable death, unattended death, or matter of routine

Coroner

an elected official, confirm and certify death within jurisdiction.

Medical Examiner

medically qualified appointed official, investigate deaths and injuries that occur under unusual/suspicious circumstances.

Forensic Pathologist

medically qualified appointed official specialized in forensic pathology, performs post-mortem exams for legal purposes

Forensic Pathology

involves the investigation of unnatural, unexplained, or violent deaths.

Duties include: determining the cause; manner or death; time of death

Autopsy

examination of a body after death; AKA a postmortem examination

The goal of the forensic/medicolegal autopsy is to determine the

cause of death, confirm the manner of death, criminal proceedings, and the time of death

Clinical/hospital autopsy

confirms clinical diagnosis, disease, any other possible medical conditions.

forensic autopsy

internal/external findings, correlations between injuries and crime scene.

Broad examination of the body

- Match clothing damage to body damage

- Physical measurements, scars, tattoos, piercings, punctures, tracks, etc.

- Any visual evidence of medical intervention as well as review of medical record.

classify and describe injuries

classifying the injuries/ distinguishing between different types of wounds:

-photographs and metrics of all injuries

-X-Rays

-gunshot wounds and stabbings, fragments, path of projectile, current or old bone damage

dissection of the human body

Generally the removal of all internal organs through a Y-shaped incision beginning at the top of each shoulder and extending down to the pubic bone.

internal examination

entails weighing, dissecting, and sectioning each organ of the body

-microscopic examination of heart, lung, liver, etc.

-may be important for determining cause, mode, or other factors contributing to general health status of decedent prior to death.

microscopic examination

of heart, lung, liver, etc.

-may be important for determining cause, mode, or other factors contributing to general health statues of decendent prior to death

stomach and small intestine contents

pills, timing of last meal based on extent of digestion, toxicology analysis

scene investigation- medical

Crime scene with the body present

-At the scene:

-Documenting/photographing undisturbed body and surrounding area

-Collect relevant evidence on or around body

-Attempt to determine time of death

-Can make some initial observations

-Have to remove body in a medically acceptable manner

Otzi

Natural mummy found in Otzal Alps that was radio carbon dated to 3,300 BC. Found on December 19th, 1991, cause of death could be a violent death due to his autopsy.

Cause of Death (COD)

The direct action or mechanism that results in death

Common causes of death

-blunt force injury

-sharp force injury

-asphyxia

-gunshot wound

-substance abuse

Blunt force trauma

injury caused by a blow that does not penetrate the skin or other body tissues. can cause abrasions, contusions, lacerations, fractures, and dislocations of bone

Contusion (bruise)

rupture of blood vessels causing hemorrhage immediately underneath the skin

Lacerations

bursting open of the skin, caused by compression and stretching of the skin, irregular edges

fracture

break, rupture or separation of tissue(usually bone)

Dislocation

disturbing the normal position, usually where two bones meet at a joint

pattern injuries- blunt force trauma

identifies the cause of the bruise.

measurements- include a ruler in the photo

photograph- take one photo at 90 degrees

sharp force trauma

well-defined separation of tissues, usually from weapons with sharp edges, such as knives or blades. stabs, chops, incisions (slashes).

determining the tool used

Angle of the incision

Shape of the incision

Number of incisions

Depth of the incision

defensive wounds

an injury received by the victim of an attack while trying to defend against the assailant. often on hands, forearms, sometimes on legs. trying to protect face, chest and neck. Good location to swab for DNA

asphyxiation

asphyxia encompasses conditions that interfere with the intake of oxygen. Physical injuries to the mouth and face. bruising patterns, defensive marks, and additional physical signs.

Suffocation (Mechanical)

facial contusions or bruises, tongue bite, lip injuries, broken nose, fibers or materials in nose/mouth

strangulation

Caused from constriction of the neck by ligature or manually (throttling).

-May see damage to windpipe and/or hyoid bone

-May see defensive wounds around face and neck

hyoid bone fracture

the hyoid bone is rarely fractured during suicide attempts

hanging

death by blood vessel compression or fracture and dislocation of cervical spine

-how victim was hanging

-position of noose and knot

Petechial hemorrhages

Pinpoint flat round red spots under the skin surface caused by intradermal hemorrhage

-are common in strangulation cases: eyelids, mouth, face

-rare in suicidal hanging deaths

are petechial hemorrhages more common in suicides or homicides?

homicides

gunshot wounds

originate from projectiles fired by a firearm. The distance a weapon was fired from a target is one of the most important factors in characterizing a gunshot wound.

entrance wounds

-Four categories based on range: distant (or indeterminate), intermediate (medium), close, contact.

-Diameter of tattooing, presence of soot, and collaring - help determine distance.

collaring

tissue damage surrounding the entry wound of a projectile

contact gunshot wound

-center dark area is from gunowner residue

-barrel markings are common

-type of weapons can be matched to the skin markings

-stellate pattern

-contains gun powder residue indicating it was a contact wound

close rang, 2-6 inches

-Stippling from hut gunpowder exiting the barrel as it is fired

-Stippling may differ because of grain size

-Less stippling on the side of the wound where the bullet entered

-Stippling pattern is 1-2 inches in diameter

intermediate, 1-3 feet

-Stippling pattern is very disperse

-stippling pattern is very symmetric

-stippling pattern is 4-12 inches in diameter

distant, greater than 3 feet

-Dark color is from postmortem drying

-No stippling from gunpowder

-Redness is from tissue damage

-No soot/powder inside the wound

Overdose Death

scene of death may have enough indication to determine death as an overdose.

Injection sites

-injection sight disguise(tattoo)

-track marks or bruised needle marks left on skin

-track marks

-skin popping; injecting a bubble under the skin

overdose indications

-"foam cone", result of anoxia following pulmonary edema

-stomach contents

-brain swelling

toxicology

-Tissues, organs, and body fluids are retained for pathological and toxicological examination

important in poision and drug abuse cases

-blood, bile, urine, stomach contents, liver, vitreous humor, cerebral-spinal fluid, lung, muscle, bone marrow

blood is routinely tested to...

determine the presence and levels of alcohol and drugs

some drugs redistribute after death - post mortem drug redistribution so you should...

collect blood samples from different anatomical sites - superior and inferior venous systems

toxicology-blood

contains most foreign chemicals

toxicology-bile

morphine, MDMA, buprenorphine, tramadol

toxicology-brain

Morphine, cocaine, and mercury

toxicology-urine

morphine, meth, heroin, cocaine, THC

toxicology-stomach contents

orally administrated drugs

toxicology-hair

all substances

toxicology-vitreous humor

alcohol, glucose, urea, creatine

Manner of death

How death occurred; 5 possibilities

- natural

-accidental

-suicide

-homicide

-undetermined

homicide

none-accidental death resulting from gross negligence, reckless, or intentional actions of another person

Types of homicide

-failure to provide: food, water, medical care

-DUI driving

-weapon

-poisoning

-premedication

-hiring a hitman

suicide

taking of one's own life with lethal intention; must be determines that decedent carried out the act alone

common types of suicide

-gunshot

-hanging

-drug overdose

-jumping

accidental death

death resulting from an unusual event that was unanticipated by everyone involved-not intended, expected, or foreseeable.

types of accidental death

-traffic accidents

-drug overdose

-drownings

natural death

attributed to an illness or physiological malfunction of the body independent of external forces.

types of natural death

-illness

-disease

-old age

-chronic drug or alcohol abuse

undetermined death

reasonable classification cannot be determined.

why deaths are undetermined

-mechanism wasn't found at autopsy

-lack of findings in toxicology and/or microscopic examinations

-might be changed after more investigation, more sophisticated testing

The following evidence is collected and sent to the forensics lab during the autopsy:

-Decedent's clothing

-Fingernail scrapings or cuttings

-Head and pubic hairs(pubis hairs for sex related crimes)

-blood or buccal sample for DNA typing comparisons

-vaginal, anal, and oral swabs(sex-related crimes)

-recovered bullets from body

-hand swabs from shooting victims(gunshot residue, GSR)

-swabs of the body areas suspected of being in contact with DNA from touching or saliva

-trace evidence

estimating time of death

A pathologist can rarely give an exact time of death. However, there are many characteristics that the examiner can analyze in order to arrive at an approximate time of death.

investigators gather as much evidence as they can from...

-witness accounts

-temperature and state of area around body

-dates on mail, meal/dishes

States of Physical Change

-algor mortis

-livor mortis

-rigor mortic

Algor Mortis

the body temperature continually cools until it reaches the ambient/room temperature

Average oral body temperature

98.6°F (37°C)

rectal or ear temperature is higher than oral, true or false

true

armpit temperature is higher than oral, true or false

false

body temperature

ear, rectal, or liver temperatures. Taken at scene as soon as possible

how much heat does the body lose in the first hour?

roughly 2.0° F

how many degrees does the body lose per hour until is reaches the enviromental temperature?

1.0° F to 1.5° F/hour

what does the rate of temperature lose depend on>

ambient temperature, humidity, and clothing.

livor mortic

the settling of blood in areas of the body closest to the ground

when does livor mortis begin?

begins 20 minutes after death and continues for up to six hours

lividity(coloring)

pinkish-red or deep purple with heart failure and asphyxia

what do different lividity patterns mean?

the body may have been moved

blanching of the skin

applying pressure to area of livor mortis might result in blanching for a time

if someone blanches, are they within the 16 hour window for livor mortis?

yes. they are within the 16 hour window

if there is no change, is the body within the 16 hour window for livor mortis?

no, they are past the 16 hour window

items pressing on the skin result in...

permanently blanched patterns after 16 hours

the blanching patterns helps to identify:

if the body has been moved, and if the position of the body has changed.

blanching impressions

clothes, fabric, and objects pressing on the skin result in blanching patterns

Adenosine Triphosphate (ATP)

one of the principal chemical compounds that living things use to store and release energy

rigor mortis

begin 5 hours post mortem, head, neck, then extremities-disappears after 36 hours

Why does rigor mortis occur?

occurs since the body energy source(ATP) is depleted, muscles need ATP to relax

rigor mortis occurs in all muscles so...

the skin will appear to have goose bumps during this time

decomposition

decay or putrefaction, primarily from intestinal microorganisms

after death...

no functional immune system, abdomen develops green discoloration after 24-36 hours

why do corpses bloat 2-3 days after death?

bacteria in the body produces gas, causing belly and face bloating

Corneal clouding

present in the early stages of decomposition

four main types of species that feed on dead organisms

-necrophages

-predators and parasites

-bury beetles and rove beetles

-hister beetles, ants, bees, and wasps

types of reconstruction evidence

-Physical Evidence

-Circumstantial Evidence

-testimonial Evidence

-Reenactments

-Solid timelines is required

for all crime scenes

deductive reasoning

the process of drawing logical conclusions based on known facts or premises