{

Aim: SWBAT describe the stages of decomposition of a corpse Date: May 7, 2013Do Now: 1. Get out the worksheet from

yesterday. 2. Calculate the time of death for a

body found at 26° C.

16 hours and 12 minutes

Solution

Homework Review Decomposition Introduction

Eye Changes Stages of Decomposition Red Light

Agenda

1. 5 hours2. Before 5 hours3. 14 hours 14 minutes4. 31 hours 42 minutes5. 57 hours 24 minutes6. 9 hours 42 minutes7. 16 hours 36 minutes8. A) Reduce B) Reduce C) Increase D) Reduce

Homework Review

Breakdown of tissue, organs, and other remains

http://www.youtube.com/watch?v=KkNdCSW1n_g

Decomposition

Eye dries out, thin film forms over it

Forms within 2-3 hours if open at death, 24 hours if closed

Potassium buildup in the eye

Changes in the eye

Answer the following in your notebooks:As forensic scientists, how can we utilize the information from sites like the body farm in our investigation?

Red Light

http://www.youtube.com/watch?v=7e6jxW07RdU

Stages of Decomposition

1. Within two days (Initial Decay)a. Livor Mortisb. Discoloration in facec. Marbling of skind. Cell Death

Stages of Decomposition

2. Four days ( Putrefaction)a. Blistersb. Stomach swells with gas from

bacteria

Stages of Decomposition

3. 6 – 10 Days (Black Putrefaction)

a. Gases build upb. Chest and Stomach burst and collapsec. Fluids leak from bodyd. Eyes liquefye. Skin sloughs off

Stages of Decomposition

4. After 10 days (Butyric fermentation)

a. Corpse starts to dry out, flesh is gone5. Eventually (Dry decay)

a. Corpse is dry, little decay

Stages of Decomposition

Answer the following in your notebooks:1. How can we recognize the first stage of

decomposition?2. Describe the second stage (putrefaction) of

decomposition?3. How does the body change from the second

stage (putrefaction) to the third stage (black putrefaction) of decomposition?

4. In your own words, describe what occurs during the fourth (Butyric fermentation) and fifth (Dry decay) stages of decomposition.

Red Light