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