Forensic Medicine: Post-Mortem Changes Basics

UGC-NET Forensic Science Unit X drill covering the sequence and medico-legal interpretation of post-mortem changes. The mock addresses algor mortis (body cooling at 0.83 to 1 degree Celsius per hour under standard ambient conditions), livor mortis (post-mortem hypostasis, onset 1 to 3 hours, fixation 6 to 12 hours), rigor mortis (onset 2 to 4 hours, fully established 6 to 12 hours, and resolution at 24 to 36 hours in the Indian climate), putrefaction (green discolouration beginning at the right iliac fossa, marbling of superficial veins, and bloating), adipocere formation (saponification of body fat in humid or waterlogged conditions over weeks to months), and mummification (desiccation in dry hot environments). Stomach content gastric emptying patterns and the progressive rise of potassium in vitreous humour (vitreous K+) as a biochemical marker of post-mortem interval are also covered.

The Indian context is woven throughout. Rigor timings reflect the accelerated cycle observed in the Indian tropical climate. The legal framework cites Section 194 of the Bharatiya Nagarik Suraksha Sanhita (BNSS) 2023, which replaces Section 174 of CrPC 1973, governing inquest and post-mortem examination orders. References draw on Modi's Medical Jurisprudence and Toxicology (latest edition edited by K.S. Narayana Reddy, 35th edition), Reddy K.S. Narayana's own Essentials of Forensic Medicine and Toxicology, and Knight and Saukko (Knight's Forensic Pathology, 4th edition). AIIMS Delhi and GMC mortuary practice standards underpin several questions on the sequence and documentation of post-mortem changes.

Topics covered:

• Immediate signs of death: cessation of respiration, circulation, and brain activity
• Algor mortis: body cooling rate and environmental factors
• Livor mortis: onset, distribution, fixation, and investigative significance
• Rigor mortis: onset, progression, resolution, and Indian climate timings
• Putrefaction: green discolouration at right iliac fossa, marbling, bloating
• Adipocere and mummification: conditions, timeline, and forensic value
• Stomach contents and gastric emptying as post-mortem interval indicators
• Vitreous humour potassium rise as a biochemical PMI marker

Calibrated for first-pass UGC-NET Forensic Science Paper II preparation, NFSU MSc Forensic Medicine entrance, and AIIMS MSc Forensic Science revision. Allow 30 minutes.