1. Time of Death Determination
Livor Mortis
Rigor Mortis

2. Livor Mortis – Color of Death
Settling of blood after death
Gravity causes blood to settle at lowest spot
Apparent 20 minutes – 4 hours after death
Not “fixed” (non-changing) for ~ 3 hrs (blanching upon finger pressure)
6-8 hrs will be fixed

3. Variables to Consider Bodies in water, etc. where no fixed position
Situations w/o gravitational effect (spacecraft murder?)
Decomposition
Suntan/dark skin
Anemia
Massive loss of blood

4. Visual Appearance Usually dark red or purple
Carbon monoxide poisoning, cyanide results in cherry red or pink appearance
Likewise exposure to cold will affect

5. Rigor Mortis – Stiffness of Death
Chemical changes after death cause muscle tightening
Starts in small muscles and moves to larger
Muscles of face and jaw usually go first
3 hrs. – no effect
4-6 – neck and jaw
6-8 – more advanced throughout body

6. Rigor Mortis 12 hrs – full rigor
18-24 hrs – begins resolving, head and jaw are slack
30 hrs – rigor resolved, body limp

7. Rigor Mortis
Chemical changes involve accumulation and breakdown of adenosine triphosphate (ATP)
ATP is the facilitator of muscle movement
When ATP depleted, full rigor results
Loss of rigor due to muscle fiber decomposition

8. Rigor Variables Muscular individuals experience to higher degree
Antemortem activity can deplete ATP and speed up onset
Death in sleep can slow down due to more ATP at death

9. Cadaveric Spasm – a Rarity
Onset of rigor is instantaneous but diminishes in normal manner
Brought on by sudden, violent impact such as instantly fatal gunshot wound or collision
Happens but extremely rare