Forensic Medicine — MLC, Postmortem & Injuries for NEET PG 2026

Master forensic medicine for NEET PG 2026 — medico-legal cases, postmortem changes, mechanical injuries, asphyxia, BNS 2023, IEA 1872, POCSO Act.

Postmortem changes — the time-since-death timeline

Time-since-death estimation tools

• Body temperature — rectal temperature is the most reliable. Glaister equation: TSD (hr) = (98.4 − rectal temp °F) / 1.5.
• Rigor mortis status — described above.
• Stomach contents — partially digested food suggests death within 2-4 hr of last meal.
• Bladder contents — minimal urine suggests recent voiding.
• Vitreous potassium — rises linearly post-death (~0.17 mEq/L/hr).
• Eye changes — Tache noire (drying of sclera) at 2-3 hr if eyes open; corneal opacity at 6-12 hr if eyes open; cloudy at 12-24 hr if closed.

Cadaveric spasm

A separate phenomenon from rigor — instantaneous post-death contraction at moment of death, often clutching an object (weapon, grass during drowning). Indicates intense emotional/physical state at death; medico-legally important for suicide vs homicide.

Mechanical injuries — blunt and sharp force

Blunt force injuries

Bruise dating is approximate and influenced by depth, location, age. Tissue bridges distinguish laceration (blunt) from incised wound (sharp).

Sharp force injuries

Defence wounds

Cuts on palms, ulnar borders of forearms, and dorsum of hands while warding off the assailant — strongly suggestive of homicide. Located on parts the victim raises in self-defence. Self-inflicted (suicidal) wounds are typically multiple parallel "hesitation" cuts on accessible non-vital areas (anterior wrist, anterior neck).

Firearm wounds

Exit wounds are typically larger, irregular, everted, and lack abrasion collar, scorching, or tattooing. Shored exit wounds (against a hard surface) can mimic entry and confuse investigators.

Asphyxial deaths

Hanging vs strangulation — the classic forensic comparison

Manual strangulation (throttling) typically has fingertip-shaped contusions and crescentic abrasions from fingernails on the neck. Garrotting is ligature applied with twisting force.

Drowning

• Wet drowning (~85%) — water aspirated; froth at mouth/nostrils, water in airway, washerwoman skin (pruning) of palms and soles, cutis anserina (goose flesh).
• Dry drowning (~15%) — laryngospasm; little water in lungs.
• Diatom test — diatoms recovered from femoral marrow indicates drowning (water reached circulation while heart was beating). Negative test does not exclude drowning.
• Distinction — antemortem submersion has water in stomach and lungs; postmortem submersion typically does not.

Sexual assault medical examination

Governed by POCSO Act 2012 (children <18) and BNS 2023 / IEA 1872 (adults).

Examination principles

• Examination by female doctor wherever feasible; in presence of female attendant; child-friendly approach for minors.
• Informed consent in patient's language; for minors, guardian consent + child's assent.
• Audio-video recording where possible.
• Two-finger test is illegal and unscientific (Supreme Court ruling 2013, reiterated 2022). Hymen is not a reliable indicator of virginity.
• Document general physical exam, mental state, clothing, evidence of struggle, genital and anal examination findings.

Forensic samples (within 96 hours optimal, up to 7 days for DNA)

• Vaginal, oral, anal swabs and smears
• Pubic hair combings and clippings
• Fingernail scrapings/clippings
• Blood for DNA, alcohol, drugs of abuse
• Urine for drugs (especially in suspected drug-facilitated assault — benzodiazepines, GHB, ketamine)
• Clothing in separate paper bags

Recent law changes — BNS 2023

The Bharatiya Nyaya Sanhita 2023 has replaced the Indian Penal Code 1860 (effective 1 July 2024). Relevant sections:

• Rape (BNS Section 63) — corresponds to old IPC 375/376; broader definition; minimum 10 years to life imprisonment.
• Gang rape (BNS Section 70) — minimum 20 years to life.
• Rape causing death or vegetative state (BNS Section 66) — death or 20 years to life.
• Rape of minor <12 — death or life imprisonment.
• POCSO 2012 still applies for children <18 and provides additional protections.

Poisoning — Indian law and clinical priorities

The forensic doctor must distinguish accidental, suicidal, and homicidal poisoning, and preserve viscera for chemical analysis.

• Common Indian poisons — organophosphates (commonest agricultural suicide agent), aluminium phosphide (Sulfas tablet, very high lethality), kerosene/paraffin (paediatric accidental), corrosive acids/alkalis, paracetamol, alcohol, datura, oleander, snake venoms.
• Viscera preservation — stomach + contents, small intestine + contents, liver + kidney, blood, urine, vitreous humor — preserved in saturated saline (NOT formalin); organophosphate samples in plain container (no preservative).
• Chain of custody — sealed container, signed labels, magistrate-witnessed dispatch to FSL.

Indian medico-legal framework — quick reference

High-yield NEET PG MCQ traps

1. Tardieu spots — petechial haemorrhages under pleura/pericardium in asphyxial deaths.
2. Paltauf hemorrhages — subpleural patches in drowning.
3. Greenish discolouration of putrefaction starts at right iliac fossa.
4. Rule of nine for burns in adults; differs in children — head 18%, each leg 14%.
5. Patterned bruise preserves shape of weapon (rod, belt, hand).
6. Suicidal cut throat wound — multiple, parallel, on left side (in right-handed); hesitation marks; spares deep structures initially.
7. Homicidal cut throat — usually single, deep, transects vital structures, no hesitation cuts.
8. Brain death criteria (THOA 2011) — apnoea test, absent brainstem reflexes, two examinations 6 hr apart, board of four doctors.
9. Heat stroke vs hyperthermia — heat stroke is loss of thermoregulation with core temp >40°C and CNS dysfunction; in postmortem, fixed lividity is bright red (carbon-monoxide-like).
10. Fingerprints — Henry classification (loops, whorls, arches); never identical even in monozygotic twins.

Recent updates and Indian context

• BNS / BNSS / BSA 2023 — replaced IPC 1860, CrPC 1973, IEA 1872. Effective 1 July 2024. Section numbering has changed; expect explicit naming in NEET PG questions.
• MTP Act 2021 amendments — extended upper limit to 24 weeks for specified categories; recognised unmarried women's right to abortion.
• Two-finger test — declared unconstitutional, professionally unethical; mention is a frequent NEET PG trap.
• NMC Act 2019 — replaced Indian Medical Council Act; introduced National Exit Test (NExT).
• Mental Healthcare Act 2017 — decriminalised suicide attempts; key cross-question with psychiatry.
• Indian Medical Association directives — mandatory dual signatures on MLC reports; preserved hospital records minimum 3 years (10 years for medico-legal cases).

Frequently asked questions

What constitutes a medico-legal case (MLC)?

Any case where attending physician suspects need for legal investigation — assault, RTA, burns, poisoning, suspected suicide or homicide, sexual assault, dowry death, dog bite, custodial injury, drowning, electrocution, suspicious unattended death, brought-dead cases. The doctor is legally obligated to inform police and document findings without sharing the body until permitted.

What is the order of postmortem changes after death?

Pallor mortis (immediate, paleness from circulatory arrest), algor mortis (cooling at ~1°C/hour), rigor mortis (begins 2-3 hr, fully developed 12 hr, passes off 24-36 hr), livor mortis (1-2 hr, fixed by 6-8 hr), then putrefaction beginning at right iliac fossa with greenish discolouration after 24-48 hr in tropical climates.

How do you differentiate hanging from strangulation?

Hanging — ligature mark is high on neck above thyroid cartilage, oblique, non-continuous (gap at point of suspension), pale and parchment-like; minimal external trauma. Strangulation — mark is below thyroid, horizontal, continuous around neck, often with abrasions, contusions; petechiae prominent, signs of struggle present. Hyoid fracture more common in strangulation.

What does the POCSO Act 2012 mandate for child sexual abuse cases?

Protection of Children from Sexual Offences Act protects all children under 18. Mandates reporting by anyone with knowledge or suspicion (failure to report is punishable). Examination by female doctor in presence of guardian or female attendant, audio-video recording where possible, child-friendly procedures, in-camera trial within 1 year, no aggressive cross-examination. Two-finger test is illegal.

What are the legal requirements for medical termination of pregnancy in India?

MTP (Amendment) Act 2021 allows termination up to 20 weeks on opinion of one registered medical practitioner; up to 24 weeks on opinion of two practitioners for specific categories (rape, incest, minors, mentally ill, fetal abnormalities, change in marital status). Beyond 24 weeks only with Medical Board approval for substantial fetal abnormalities. Confidentiality is mandatory.

Written by: NEETPGAI Editorial Team Reviewed by: Pending SME Review Last reviewed: April 2026