Forensics Chapter 12 (Finals)

5 different manners of death

natural, suicidal, homicidal, accident, undetermined

Cause of death vs mechanism of death

The reason why someone dies, an event that causes someone to die;

the specific change in body that causes cessation of life

Livor Mortis

The pooling of blood in tissues after death that results in a reddish-purple skin color

.Lividity

Discoloration of skin, reddish-purple skin color

.When does lividity first begin?

2 hours after death

.When is the color permanent?

8 hours after death

.Dual lividity

Lividity is found in two different areas of the body

.How does dual lividity show that the body has been moved?

Dual lividity could occur if the body was kept in one position two hours after death and then moved to a second position before the lividity became permanent in 8 hours

.Rigor mortis

The temporary stiffening of the skeletal muscles after death

.Factors affecting rigor mortis

• Temperature (cold stops, warm accelerates)

• activity before death (exercise accelerates, sleep slows)

• body mass (obese slows, thin accelerates)

.Time after death if rigor is present in the face and neck

2-6 hours

.When is peak rigor attained?

12 hours after death

.Algor mortis

Cooling of the body after death

.Rule of Thumb PMI estimates

warm and limp (less than 3 hours)

warm and stiff (3-8 hours)

cold and stiff (8-36 hours)

cold and limp (more than 36 hours)

.Stages of decomposition

a. fresh: corpse appears normal but is decomposing internally; body temperature drops;

b. bloating: odor begins, corpse appears swollen, lividity, may split open from gases, fluid seepage

c. active decay: strong odor, discolored flesh, skin ruptures to allow gas escape and body collapse, body mass lost to insects

d. advanced decay: corpse dries out, most flesh is gone, fewer insects

e. dry/skeletal: mostly bone remains

.Forensic autopsy; what does it not require?

Autopsies performed when foul play is suspected; permission of family

.Autolysis

Cell self-destruction

.Blunt force trauma

Trauma from a blunt object on the body; blown pupil or fully dilated pupil on the side of the head where the injury was sustained; bleeding under the membrane that surrounds the brain

.normal body temperature:
in the first 12 hours, body loses…
after the first 12 hours, body loses…

37C
9.36C in total
.39C per hour

Coroner and duties

An elected or appointed government or judicial official who can

- identify the body

- notify the family

- collect and return personal items

- issue a death certificate.