Page 126 - CFDI Guide

Livor Mortis is the settling of the blood and is generally a more consistent factor, although still reliant

on any of the aforementioned factors. This is usually fully developed in 2-4 hours, then blanches to
pressure in 2-12 hours, and fixed – no blanching – in about 12 hours. Color may vary and may be an

indication of the Postmortem Interval (PMI – time from death to discovery), or other factors (chemical
cherry red, ligature congestion, etc.).

Algor Mortis is the cooling of the body, at in ‘ideal’ conditions is about 1.5 degrees per hour. There is

no reliable accuracy to this based on several of the aforementioned conditions. As a general
consideration with other factors, this temperature change is used.

Rigor Mortis is a release of adenosine triphosphate (ATP) at death and progresses through stages.

These stages are generally reliable, and still contextual with the other signs and aforementioned
factors. Onset usually begins in 30 minutes to two hours, then is fixed (stiff) in 8-16 hours, and passes

(releases) in 24-36 hours.

Each of the above factors, and the aforementioned conditions, are taken into account to determine a
window for TOD / PMI. Accuracy is dependent on these factors and interpretation.

III. Changes After Death

Decomposition begins internally after death as the body chemically breaks down, and bacterial

growth. Signs of decomposition progress in stages, usually beginning in the abdomen (stomach and
intestines), with marbling, bloating, discoloration, foul odor, purging (nose and mouth), and skin
slippage and splitting. Final stages of decomposition are mummification and skeletonized remains. This

time of decomposition varies greatly with environments – inside and outside, location, etc. Florida will

differ from the seasons of Colorado, and Colorado will differ with the seasons of Alaska. Maggots and
flies can be very important to TOD. From the laying of eggs to larvae to hatching – each has a

progressive stage. Collection of all insect artifacts from scene and autopsy are important. These
findings are examined by a forensic entomologist if further examination of insects are vital to the

investigation (the study of entomology – scientific study of insects, etc.).

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