Forensic Science: Death Investigation and Postmortem Changes

Vocabulary-style flashcards covering death definitions, forensic roles, autopsy procedures, manners of death, and postmortem changes like rigor, livor, and algor mortis.

Death (Forensic Science)

The permanent and irreversible cessation of all vital life functions, including heartbeat, breathing, and brain activity.

Coroner

An elected official who may lack medical training, responsible for investigating deaths, ordering autopsies, and signing death certificates, typically in smaller or rural communities.

Medical examiner

A licensed physician and appointed official, usually trained in forensic pathology, who performs autopsies and determines the cause and manner of death.

Forensic Pathologist

A medical professional who performs autopsies, studies injuries and diseases, determines cause and manner of death, and collects evidence from the body.

Autopsy

A medical examination of a dead body performed to determine the cause of death, manner of death, and the presence of injuries, disease, drugs, or poisons.

External Examination

The first step of an autopsy where the body is examined without being opened to document height, weight, identifying marks, and visible injuries.

Internal Examination

A stage of an autopsy beginning with a Y-shaped incision to open the chest and abdominal cavity so organs can be weighed, dissected, and sampled.

Toxicology

The study of drugs, alcohol, poisons, and chemicals in the body using samples such as blood, urine, hair, stomach contents, and vitreous humor.

Vitreous humor

The eye fluid tested during toxicology screens and used to measure potassium levels for estimating time of death.

Cause of Death

The specific injury or disease responsible for death, such as a gunshot wound, heart attack, or drug overdose.

Manner of Death

The category describing how a death occurred: Natural, Accident, Suicide, Homicide, or Undetermined.

Natural Death

A manner of death caused solely by disease or aging, such as cancer or a stroke.

Blunt Force Injury

Trauma that occurs when the body is struck with a non-sharp object like a hammer or car dashboard, resulting in bruises, abrasions, or broken bones.

Sharp Force Injury

Trauma caused by sharp-edged objects like knives or razors, categorized into incisions (longer than deep) and stab wounds (deeper than long).

Asphyxia

A condition occurring when the body does not receive enough oxygen, often indicated by petechiae, blue lips, or neck bruising.

Petechiae

Tiny burst blood vessels that are a common sign of asphyxia.

Algor mortis

The cooling of the body after death, typically occurring at an average rate of $1.5\,^{\circ}F/\text{hour}$ from the normal $98.6\,^{\circ}F$.

Ambient temperature

The surrounding environmental temperature which can speed up or slow down decomposition and the cooling of a body.

Livor mortis

The pooling of blood in lower parts of the body due to gravity, causing purple/red discoloration that begins about $2$ hours after death and becomes fixed after $8-12$ hours.

Rigor mortis

The stiffening of skeletal muscles after death because cells stop producing ATP, beginning $2-6$ hours after death and disappearing after $24-36$ hours.

Potassium Eye Levels

A method of estimating time since death based on the steady rise of potassium levels in the vitreous humor as cells break down.

Decomposition

The natural breakdown of body tissues after death, affected by temperature, moisture, insects, oxygen, and burial conditions.

Fresh Stage

The first stage of decomposition immediately after death involving algor, livor, and rigor mortis with little odor.

Bloat Stage

The second stage of decomposition where bacteria release gases, causing the body to swell, produce a strong odor, and turn green/purple.

Active Decay

The third stage of decomposition characterized by rapid soft tissue breakdown, strong odor, leaking fluids, and increased maggot activity.

Dry/Skeletal Stage

The final stage of decomposition where mostly bones, hair, and cartilage remain.

Putrefaction

Rotting caused by bacterial decomposition, resulting in green discoloration, gas formation, and tissue breakdown.

Adipocere

Also known as "grave wax," it is a waxy, gray/white substance formed when body fat breaks down in wet or moist environments, preserving tissues.