HOSA-forensic science case study

2-6 hours after death

rigor begins

2- 6 hours after death appearance

body becomes stiff and stiffness moves through body

2-6 hours after death circumstances

stiffness begins in small muscles, such as those of the face, and progresses to larger muscle groups

12 hours after death

rigor complete

12 hours after death appearance

peak rigor is exhibited

12 hours after death circumstances

entire body is rigid

15 to 36 hours

slow loss of rigor

15 to 36 hours appearance

rigor is uneven

15 to 36 hours after death

rigor is slowly first in smaller muscles and later in larger muscles

36-48 hours after death

rigor absent, Decomposition begins

36-48 hours after death appearance

muscles are relaxed

36-48 hours after death

many variables may extend rigor beyond the normal 36 hours

factors affecting when rigor morris sets and how long it lasts

1. surrounding temperatures

2. persons weight

3. presence, absence, and weight of clothing

4. illness

5. level of physical activity shortly before death

6. exposure to heat, cold, sun and wind

livor mortis (lividity)

"death color" results when blood cells settle

What is lividity (livor mortis)

reddish purple color that results as blood vessels break down

lividity becomes permanent after ____ hours

8

lividity shows after ____ hours after death

2

lividity within 2-8 hours

coloration will disappear when skin is pressed

lividity after 8 hours

coloration is permanent

when does rigor mortis become apparent

2 hours after death

when is body at most rigid state(rigor mortis)

after 12 hours

if a body shows no visible rigor...

it has probable been dead less than 2 hours or more than 48

rigor mortis stiffness occurs because

bc skeletal muscles are unable to relax

1. several hours after death

-cell autolysis begins

-muscles lose tone

-bladder and rectum empty due to loss of muscle control

-onset of algor,livor, and rigor mortis

-cloudy film over eyes if left open

-flies arrive to lay eggs

2. several days after death

-blistering of skin=skin slippage

-putrefaction

-bloating

-internal pressure from fluids

-gases may force fluid from body openings

-marbling(skin discoloration)

-loss of rigor mortis

-increased insect activity

3. days 7-23 after death

-bloating continues

-discoloration of skin makes it impossible to tell skin color

-ruptures in skin occur

-soft tissues start to liquefy

4. 3 weeks to 2 months

-greatest loss of mass occurs due to insect infestation

-fats undergo decomposition forming adipocere

5. 2 months after

-soft tissues fone

-bones remain

-odors mostly gone

fresh(initial) decomposition

corpse appears normal on outside, but is starting to decompose from the actions of bacteria and autolysis

body temp drops

insects lay eggs

bloating(putrefaction)

odor of dead flesh

corpse appears swollen

skin becomes marbled

may split from gases resulting in seepage

increased insect activity

Active Decay (Black Putrefaction)

3rd stage of decomposition

Days 10-20, (gas escapes, odor, maggot masses) flesh colored skin

Advanced Decay

corpse is drying out

most flesh gone

adipocere forming

fewer insects remain

Dry or Skeletal Decay

mostly bones remain

What is adipocere?

a yellowish-white, greasy, wax-like substance that forms from the fat of the body

what happens to open eyes within _____ hours

2-3, get cloudy

how many hours will the eyes get cloudy if they are closed or covered

24

body feels warm and limp

less than 3 hours

body feels warm and is stiff

3-8 hours

body feels cold and is stiff

8-36 hours

body is cold and limp

dead more than 36 hours

after first 12 hours body cools at a rate of

.39 c or .7 f per hour

1hour after death the body cools

.78 c or 1.4f

What is putrefaction?

the process of decay or rotting in a body or other organic matters

if there is rigor throughout body but lack of rigor in face, jaw, neck then body is likely losing rigor...

death occurred more than 15 hours ago

if body exhibits rigor mortis in face jaw and neck then rigor_____. time of death?

has just started, just over 2 hours