The Order of Putrefaction
Forensic Pathology: Post-Mortem Decomposition Sequences
1. The Biological Process
Putrefaction is the decomposition of organic matter by microorganisms (primarily anaerobic bacteria from the gastrointestinal tract). It involves the breakdown of proteins into simpler compounds like amines (putrescine, cadaverine) and gases (hydrogen sulfide, methane).
2. Casper’s Dictum (The Rule of 1:2:8)
A rule of thumb for estimating the rate of decomposition:
- 1 week of decomposition in air =
- 2 weeks in water =
- 8 weeks buried in soil.
3. Order of Organ Putrefaction
| Order | Organ/Tissue |
|---|---|
| 1 (First) | Larynx and Trachea |
| 2 | Stomach and Intestines |
| 3 | Spleen |
| 4 | Liver |
| 5 (Last) | Uterus and Prostate |
4. Forensic High-Yield Pearls
- First Sign: The earliest external sign of putrefaction is typically “greenish discoloration” of the right iliac fossa, due to the proximity of the cecum (which has a high bacterial load).
- Variables: Decomposition is significantly accelerated by high temperatures, humidity, and insect activity (forensic entomology). It is delayed in cold, dry, or anaerobic environments.
- The “Uterus” Exception: The non-pregnant uterus and prostate are notably resistant to putrefaction, often remaining identifiable long after other abdominal organs have liquefied.