POSTMORTEM CHANGES
 
Livor Mortis
Evident 30 min - 2 hrs.
Fixed 8 - 12 hrs. (24 - 36 hrs if cool)
Tardieu spots 18 - 24 hrs.(2 - 4 hrs in hanging limbs)
 
Rigor Mortis
Cadaveric spasm heavy exercise, convulsions, high body temps
Evident 2 - 4 hrs. (jaw, upper then lower extremities)
Maximum 6 - 12 hrs.
Passes 24 hrs (hot) - 36 hrs - 6 days (cold)
Accelerated infants, strychnine, convulsions, hyperthermia, drowning (struggle),

Cutis anserino - rigor mortis of arrector pili muscles (gooseflesh).
 
Temperature
Time since death = 37C - Rectal temp (C) + 3

Time since death = (98.6F - Rectal temp (F)) / 1.5

Assumption that body temp at death was normal.
Can have postmortem rise in temp due to metabolic activity of body tissues & bacteria: may take up to 4 hrs to return to normal.
Consider effects of ambient temperature, clothing, body fat.
 
Decomposition
Corneal clouding 24 hrs.
Green belly 24 - 36 hrs.
Marbling 60 - 72 hrs.
Skeletonization Exposed remains 9-10 days
Mummification hot & dry
Adipocere damp & warm; immersed in water
Accelerated obesity, heavy clothing, sepsis
 
Gastric Emptying
Light meal 1.5 - 2 hrs.
Medium meal 3 - 4 hrs.
Heavy meal 4 - 6 hrs.
 
Insect Activity
Blowflies lay eggs immediately after death in daytime.
Eggs 1 - 2 days
Maggots to pupa 6 - 10 days
Adult flies 12 - 18 days
 
Other Methods: Vitreous Potassium, Flow Cytometry for splenic DNA degradation (experimental)
Most accurate: Scene markers (mail, TV schedule, dress, last seen, receipts)
 
Increase post-mortem: Vitreous K, Serum glucose in asphyxia, right heart or IVC
Decrease post-mortem: Vitreous glucose, Serum Na, Cl, glucose in left heart and extremities,
Stays stable post-mortem: Vitreous Na and Cl, VUN (most stable)
 
Postmortem clot vs. antemortem clot. Postmortem looks like chicken fat & current jelly. Antemortem granular w/lines of Zahn