Forensic Science Unit 4 Flashcards
Death
Cessation of death
(in 17th century) Anyone who has a faint heartbeat or in a coma
Natural Death
Interruption of natural body functions resulting from age or disease
Homocide
Death of one person caused by another
Ways a person can die
-Natural
-Accidental
-Homicidal
-Suicidal
Cause of Death
The reason for death
Example of a cause of death
Heart attack, disease, physical injury
Mechanism of death
The specific change in the state of the body that brought about death
Example of a mechanism of death
Blood loss
Proximate cause of death
Underlying cause of death (radiation exposure)
Livor Mortis
-Lividity begins 2 hours after death
-Discoloration becomes permanent after 8 hours
- Between 2-8 hours if redden areas are pressed, color will disappear
- After 8 hours lividity is fixed and permanent
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Lividity
With decomposition, blood seeps down and settles in the lower parts of the body
What influences rate of lividity
Temperature
Dual Lividity
Lividity in two different areas which indicates that the body was moved
Rigor Mortis
-Without oxygen in the blood, muscles stiffen
-Starts two hours after death
-Begins in head and gradually works down to legs
When is the body in its most rigid stage?
After 12 hours
What happens after 12 hours of rigor mortis?
-After 15 hours, muscle fibers dissolve and softening begins
-Stiffness disappears after 36 hours
How does body weight and temperature affect rigor?
It can cause it to last for up to 48 hours
What are the factors that affect rigor mortis?
(Faster as in decomposes faster or slower as in decomposes slower)
-Temperature (cooler is slow, warmer is fast)
-Weight of body heavier is fast lighter is slow
-Clothes is faster, none is slower
-Fever is faster
- Exercise right before death is faster
-Direct sun is faster
Where is a corpse temperature taken?
The liver
What happens to eyes after death
The liquefy and rot but first turn cloudy
Algor Mortis
Time of death determined by temperature calculations which is relayed in a range of time
Where is food depending on time of death?
0-2 hours food in stomach
4-6 food in small intestine
12+ waste in large intestine
Livor Mortis Color
0-2 hours no color or change
2-8 hours lividity- blanches
8+ hours lividity is fixed and permanent
Stages of Decay
- Fresh/ Initial
- Bloating/Putrefaction
- Active Decay
- Advanced Decay
- Dry Decay
Fresh/Initial Decay
Autoanalysis, body temp drops, insteacts lay eggs, bladder and bowels empty
Bloating/Putrefactions
Cell autolysis begins
Green and purplish staining occurs
Skin takes on marbled appearance
Face becomes distorted and blisters
Bloating from C02
Active Decay
Gas causes chest and abdominal cavities to burst and collapse
Fluids leak from body openings
Eyeballs liquify
Skin comes off
Advanced Decay
Cheesy smell from butyric acid
Corpse dries out, adipocere is forming, maggots leave and beetles come
Dry Decay
Hair is consumed by moths and mites
Bones are left
What species of fly arrives at a body first?
Blowflies
What kind of gas attracts insects to a body?
When will insects lay their eggs
after 24 hours
Houseflies
Smaller than blow flies
Indicate abuse
Feeds on urine and feces
Flesh Flies
Medium sized
Black and gray stripe
Doesn’t lay eggs
Coffin flies
Size of fruit flies
may be only insect found if body is wrapped
What are the most common and numerous insects found
Beetles
Factors that affect devlopment
- Ambient environmental factors
– Clothing, temperature, time of day
– Exposure to environment
– Exposure to toxins, chemicals, drugs
Parts of a fly
Head
Abdomine
Thorax
Insect succession
insects visit a body in a fairly predictable pattern,
Reason someone dies
cause of death
Specific change in body that brought along death
Mechanism
How much warmer are maggot clumps
5-20 degrees
Temperature for blowfly development
20-50 degrees C
Accidental Death
Death that no one caused so choking would be an example
