1. Estimating the Postmortem Interval ANA315
Time Since Death
Estimating the Postmortem Interval
ANA315

2. Colonel William Shy 1838-1864 Open mind
All evidence should be considered before a conclusion is reached.

3. “Body Farm” University of Tennessee at Knoxville
3 ac of land, fenced, wooded
Experimenting with the rates of decomposition
Founder= Dr. William Bass

4. Decomposition
Change in an organism from one state to another via chemical processes

5. Techniques for PMI Body temperature Rigor mortis Lividity
Vitreous Humor
Putrefaction
Entomology – most reliable method(Dr. Mervyn Mansell)

6. Algor mortis

7. Rigor mortis
Onset and duration =environmental temperature and degree of muscular activity before death
First appears in the eyelids and moves to the lower jaw, neck and limbs
Re-establishment of rigor

8. Lividity –Livor mortis
Dark purple discoloration of the skin caused by pooling of blood
10-12 h lividity becomes fixed; movement of the body will create ‘primary’ and ‘secondary’ patches of lividity.

9. Vitreous Humor
Linear relationship between potassium concentration of the vitreous humor of the eye and PMI
Normal distribution = confidence levels are high and thus the method has no real practical application

10. Putrefaction Initial decay Early putrefaction Black putrefaction
Butyric fermentation
Dry decay
Skeletonization