FM2.{13-16,20-28},FM14.6 | Autopsy & Crime Scene Investigation — Practice Quiz

The external examination is the first and one of the most critical steps of any medicolegal autopsy. It documents clothing (trace evidence), body position findings, all external injuries, identifying features, and provides the opportunity to collect evidence before it is disturbed. Opening body cavities first destroys the external evidence hierarchy.

Medicolegal autopsy sequence: identity verification → external examination (clothing in situ + photograph) → evidence collection → undress → full external examination → internal examination.

External examination must precede internal examination. Clothing and external injuries are documented in situ with photography before any clothing is removed or internal cavities opened.

BNSS Section 176 (replacing CrPC Section 174) authorises the police to order a post-mortem examination as part of the police inquest for sudden, suspicious, unnatural, or uncertified deaths. Next-of-kin consent is NOT required — the autopsy proceeds under legal authority. A court order is not needed at the initial stage.

Two types of autopsy: (1) medicolegal — ordered by police/coroner, no family consent needed; (2) clinical — family consent required. BNSS Section 176 = authority for medicolegal PM.

Medicolegal PM: ordered by police (BNSS Sec. 176), no family consent required, no court order needed. Family consent IS needed for clinical/hospital autopsies (non-medicolegal).

In homicide autopsies, tracking each wound in situ (through skin, subcutaneous tissue, muscle, and into the organ) is essential to establish the wound track, direction, and organ injured. En masse organ removal destroys this spatial relationship, which is critical in court testimony.

Homicide autopsy key principle: track each stab/gunshot wound in situ before organ removal. Document track length, direction, organs traversed — all are evidential.

Wound track in situ examination is mandatory in homicide — it establishes trajectory, depth, direction, and the relationship between external wound and internal injury. En masse removal destroys this evidence.

Custody deaths are high-profile medicolegal cases. The key safeguard is independent witness by a second doctor and, if requested, the family's medical representative. This ensures transparency, prevents allegations of evidence concealment, and is required by NHRC guidelines. The full autopsy including internal examination must be performed.

Custody death autopsy safeguards: independent witness doctor, NHRC guidelines, full PM (not limited), videographic documentation, family representation welcome, preserve all samples.

In custody death, an independent witness doctor is mandatory — limiting to external examination would be insufficient and inappropriate. Officer consent is not required. Timing is important but not the primary additional safeguard.

In severely burned bodies where fingerprints are destroyed and facial recognition is impossible, DNA profiling is the most definitive identification method. A reference sample (buccal swab, blood) from a first-degree relative provides the comparative DNA. Dental comparison is also highly reliable IF ante-mortem dental records exist, but DNA is universally applicable.

Identification hierarchy in mutilated/burned remains: DNA (most definitive) > dental records (highly reliable, needs ante-mortem records) > fingerprints (needs intact skin) > visual (least reliable).

Severely burned bodies: fingerprints destroyed (unreliable), visual ID unreliable. Dental charting is reliable IF ante-mortem records exist. DNA is universally applicable as the most definitive method.

If the patient is critical and surgery is needed, the surgeon may retrieve the bullet during the life-saving procedure. The critical requirement is proper chain of custody documentation: the bullet must be labelled, sealed in a container, and handed over to the police with a witness receipt. At autopsy, the forensic pathologist retrieves the bullet with the same protocol.

Bullet chain of custody: retrieve only when necessary (surgery/PM); document who retrieved it, when, from where; seal in labelled container; hand over to police with signed receipt; every transfer documented.

In clinical care of a critical patient, bullets can be retrieved during surgery — but with strict chain of custody documentation. The principle is: life-saving is primary, evidence collection is secondary but must be done properly when done.

In suspected peri-anaesthetic anaphylaxis (suxamethonium, latex, antibiotics), serum tryptase (ideally collected within 4 hours of the reaction and at 24 hours post-mortem) is the most important investigation. Tryptase is released from mast cells during anaphylaxis and can be detected post-mortem. It is specific for anaphylactic/anaphylactoid reactions and must be collected early.

Anaesthetic death autopsy: collect serum/vitreous tryptase, drug levels, check anaesthetic equipment records, airway integrity. Tryptase is pathognomonic for anaphylaxis — most important test when PM is otherwise negative.

Serum tryptase is the key test for peri-anaesthetic anaphylaxis — the most common hidden cause of sudden intraoperative death with no gross findings. Collect from vitreous or blood within 4h if possible; PM levels still useful up to 24h.

Interpol's Disaster Victim Identification (DVI) guidelines use a standardised colour-coded form system: Yellow Forms for ante-mortem data (collected from family/referring agencies) and Pink Forms for post-mortem examination findings. These are matched by the DVI Reconciliation team for identification.

Mass disaster DVI: Interpol protocol — Yellow (ante-mortem) + Pink (post-mortem) forms; 4 primary identifiers: fingerprints, dental, DNA, medical records (implants); visual/circumstantial are secondary.

Interpol DVI Guidelines: Yellow = ante-mortem data; Pink = post-mortem data; matching = reconciliation. This is the internationally accepted standard and is used in mass disasters in India.

The absolute first priority at a crime scene is scene security and documentation. The scene must be cordoned off, photographed in its undisturbed state, and a log of all persons entering established. Moving the body, interviewing witnesses, or collecting evidence before documentation destroys irreplaceable contextual evidence.

Crime scene protocol: SECURITY first (cordon, access log) → DOCUMENTATION (photography, video, sketches, notes) → EVIDENCE COLLECTION → BODY EXAMINATION. Never reverse this order.

Scene security and documentation first — before body examination, before evidence collection, before witness interviews. Moving the body or collecting samples before documentation is a fundamental error in crime scene management.

The Virchow technique removes each organ individually after ligating connecting vessels and ducts in situ, then examines each separately. The Rokitansky (or Letulle) technique removes all thoracic and abdominal organs en bloc as a single unit, then separates and examines them. The Ghon technique is a hybrid. Most teaching hospitals use a modified technique.

PM dissection techniques: Virchow (individual), Rokitansky/Letulle (en bloc), Ghon (hybrid). Know the distinction — commonly tested in FM. Most Indian forensic PM uses a modified Virchow/Ghon approach.

Virchow = individual organ removal (one by one, in situ ligature). Rokitansky = en bloc removal of all organs together. Both examine all organs; neither is restricted to specific case types.

Exhumation is a legal process ordered by a court or magistrate for specific medicolegal purposes: re-examination when PM was incomplete/not done, new evidence, identity disputes, DNA profiling. Retrieval of valuables at family request is NOT a recognised medicolegal indication.

Exhumation indications: incomplete/absent original PM, new evidence in investigation, identity in doubt, DNA for paternity/inheritance, suspected poisoning. Always court-ordered. No exhumation without court order.

Medicolegal exhumation: court-ordered, specific forensic purpose (incomplete PM, identity, new evidence, DNA). Personal/family reasons (retrieving belongings) are not valid medicolegal indications.

In a suspected medical negligence autopsy, the treating doctor/surgeon has a conflict of interest. They may be allowed to observe (as a witness) but must not direct, participate in, or influence the examination. The examining forensic pathologist must be independent. Having the treating surgeon perform the autopsy would be a fundamental conflict of interest.

Medical negligence autopsy: independent forensic pathologist required; treating team may observe only; no participation/direction; family doctor may also observe; all findings documented meticulously.

The treating surgeon is a potential subject of the investigation — conflict of interest. Observation is permissible; participation or direction is not. The independent forensic pathologist must conduct the examination.