Chapter 10 - Death

Describe how stomach contents can be used to estimate time of death.

- 4-6 hours: stomach empties contents into small intestine - 12 hours: food leaves small intestine - 24 hours: large intestine

What factors can affect rigor? How do they affect it?

- Cooler temps. slow rigor - Warmer temps. speed up rigor - Naked victim cools faster and slows rigor - Clothed victim cools slower and speeds up rigor - Fever speeds up rigor - Hypothermia slows down rigor - Exercise speeds up rigor

Active Decay

- end of this stage is marked by the dispersal of the maggots from the body - also known as black putrefaction - recognizable by a great loss in mass - the body may collapse - parts of flesh may be black

Bloat Stage

- gases cause a bloated appearance of the decomposing body - skin turns a greenish color as blood decomposes - strong odor caused by microorganisms - skin may break apart and fluids flow out from the openings

Fresh Stage

- livor, rigor, and algor mortis occur during this stage - 1st stage - autolysis begins - blisters may appear at the surface of the skin

Advanced Decay

- odor and insect activity decrease - the body begins to dry and preserve itself - most of the flesh is gone

Dry Remains

- recognizable by a loss of everything on the body but dried up bone - final stage

List the six types of open wounds.

1) Abrasions 2) Incisions 3) Lacerations 4) Punctures 5) Avulsions 6) Gunshot Wounds

List the five categories of manner of death that can appear on death certificates.

1) Accident 2) Natural 3) Homicide 4) Suicide 5) Unknown

What are the three most important body systems to which severe injury can cause a sudden death?

1) Cardiovascular 2) Respiratory 3) Nervous

Name the four stages of insect development.

1) Egg 2) Larva/Instar 3) Pupa 4) Adult

List two death scenarios that do not require an autopsy.

1) Elderly 2) Terminal Illness

What are the two main types of autopsies?

1) Forensic 2) Clinical

List and describe the five stages of decomposition.

1) Fresh - all mortises occur, autolysis begins, blisters appear on skin 2) Bloat/Putrefaction - microorganism activity, production of gases, strong odor, skin turns greenish color, skin may break apart 3) Active Decay/Black Putrefaction - loss in mass due to maggots, black flesh, stronger odor, body may collapse, maggots disperse at the end 4) Advanced Decay - body is dry, most flesh is gone, odor and insect activity decrease, may form wax layer known as adipocere 5) Dry Remains/Skeletonization - only bone left

List three death scenarios that require an autopsy.

1) Homicide 2) Children 3) Unusual

Autopsies are conducted to determine what four things?

1) Manner of Death - means by which they died 2) Cause of Death - reason they died 3) Mechanism of Death - specific body failure 4) Time of Death - when they died

What two things happen to the eyes after death?

1) Surface of the eyes dries out 2) Thin film appears

Describe the rate at which a corpse cools.

1.4 degrees F/hour after death for 12 hours; slows to 0.7 degrees F/hour after 12 hours

Rigor mortis peaks how many hours after death?

12

The pooling of blood, causing discoloration, begins how many hours after death?

2 hours

Adults have __________ bones.

206

Babies have __________ bones.

300

How long is the average autopsy?

4 hours

Discoloration of skin from pooling of blood becomes permanent after how many hours?

8 hours

How can the age of a skeleton be determined?

Absence of cartilage = older

Which manner of death is the result of an unplanned event, such as a car accident or fall?

Accidental

If there is the correct level of moisture during stages of advanced decay, a layer of wax may form.

Adipocere

The cooling of body temperature after death.

Algor Mortis

How do thigh bones differ in male and female skeletons?

Angle of femur in relation to pelvis is greater in females and straighter in males

The study of the human skeletal system for purposes of identifying unknown remains.

Anthropology

If someone is strangled, they may die from lack of oxygen.

Asphyxiation

When does livor mortis begin and when does it become permanent?

Begins 2 hours after death; becomes permanent after 8 hours

When does rigor mortis begin, peak, and disappear?

Begins 2 hours after death; peaks at 12 hours; disappears after 36 hours

What is meant by the term exsanguination?

Bleeding to death

What is one of the first insects to arrive at the body?

Blowflies

What causes a dead body to become stiff? What is this condition called?

Caused by lack of oxygen to cells and calcium buildup in the muscles and joints (Rigor Mortis)

What is the purpose of a body block?

Causes chest to protrude forward while arms and neck fall back --> makes chest easier to cut open

The process of rotting and breaking down.

Decomposition

The study of insects as they pertain to crime scene investigation.

Entomology

The study of insects related to crime investigation is called what?

Entomology

What is forensic anthropology?

Examination of skeletal remains to ID bodies

If someone has been shot, they may die from loss of blood.

Exsanguination

What is the name of the computer program that enables forensic anthropologists to perform metric analyses on skeletal remains?

FORDISC

What is meant by the phrase pulmonary arrest?

Heart stopping

Why is it important for detectives to find out the time of death?

Helps exclude suspects based on their alibis or locations at that time

How does the speed of the bullet affect a wound?

High speed = largest permanent cavities

Which manner of death refers to death caused by another individual?

Homicide

How does a pathologist take the temperature of a dead corpse?

Insert thermometer into liver

Another name for the larva stage of development in insects.

Instar

What two events characterize death?

Irreversible stopping of blood circulation and brain activity

What is JPAC? Why was it founded?

Joint POW/MIA Accounting Command: founded to find, ID, and return bodies of soldiers to their families

What type of wound is difficult to treat and has a long recovery time?

Lacerations

What is meant by the term asphyxiation?

Lack of oxygen

Why do inscts arrive at the warm body within minutes?

Lay eggs

The pooling of blood in tissues after death.

Livor Mortis

The means by which someone dies (ex: homicide)

Manner of Death

The specific body failure that leads to a person's death (ex: heart failure)

Mechanism of Death

Which manner of death is most common?

Natural

What do we call a non-human postmortem examination?

Necropsy

During an autopsy, the entire organ set can be pulled out in one piece. What is this called?

Organ block

How does body size affect decomposition?

Overweight people decompose faster than thin people

Who can perform an autopsy?

Pathologist or medical examiner

What is one of the easiest methods of determining sex of a skeleton?

Pelvis

What do we call injuries that occurred at the time of death?

Perimortem

What is lividity?

Pooling of blood in the body

Besides time of death, what else can livor mortis help a forensic detective figure out?

Positioning of body or if the body was moved

What does PMI stand for? What is it?

Postmortem Interval: time between death and discovery of body

If someone has a heart attack, their heart may stop.

Pulmonary Arrest

The stage in an insect's life cycle when the insect forms a capsule around itself while it turns into an adult.

Pupa

The breakdown of organic matter caused by microorganisms, resulting in production of foul-smelling matter.

Putrefaction

What causes parts of a dead body to take on purple coloring? What is this condition called?

RBCs break and release hemoglobin which turn purple as they spill out of cells (Livor Mortis)

The stiffening of the skeletal muscles shortly after death.

Rigor Mortis

What two bones help determine the race of a skeleton?

Skull and Femur

Define "proximate cause of death" and give an example.

Specific change in the body that killed an individual (ex: exsanguination)

What is algor mortis?

Temperature loss after death

Define cause of death and give examples.

The reason a person died (ex: disease, cancer, drowning, shooting, etc.)

Who is known as the "Father of Forensic Anthropology"?

Thomas Dwight

When a person died.

Time of Death

Where is the Body Farm? Who founded it?

University of Tennessee; William Bass

What is autolysis?

When oxygen is deprived from body cells and they begin to die

Who wrote "Guide to the ID of Human Skeletal Material" that is still commonly used for forensics today?

Wilton Krogman

What is the most common cut during an autopsy?

Y-shaped incision

How does age affect decomposition?

Young decompose faster than elderly