Collection of Biological Evidence

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  • Core Pillars: Valid consent, meticulous documentation, and unbroken chain of custody are vital for evidence integrity.
  • Consent Protocol:

    ⭐ Written informed consent is mandatory for examining conscious sexual assault victims ≥18 years. For victims <18 years, POCSO Act 2012 applies where consent is irrelevant. For an accused, Sections 103 & 104 BNSS empower police to direct medical examination with legal safeguards.

  • Documentation: Detailed, accurate, and contemporaneous records are crucial.
  • Chain of Custody: Ensures evidence integrity via a documented, unbroken handling sequence.
  • Evidence Categories:
    • Physical: Injuries, torn clothing.
    • Biological: Semen, blood, saliva, DNA, urine, hair follicles, tissues, vaginal secretions.
    • Trace: Hairs, fibers.

Victim Examination & Evidence Collection - Victim's Vital Vestiges

  • Examination Protocol
    • Informed consent is paramount.
    • Two-finger test: Strictly BANNED.
    • If indicated: Gentle per speculum & per vaginum (P/V) exam by trained personnel.
  • Evidence Collection (SAECK used)
    • Sexual Assault Evidence Collection Kit (SAECK) systematically applied.
    • Optimal swab collection: As soon as possible, ideally within 72 hours for optimal DNA recovery, but evidence remains valuable beyond this timeframe (up to 5-7 days or longer).
    • Key Samples:
      • Swabs: Vaginal, cervical, oral, anal/rectal.
      • Clothing: Air-dry, separate packaging.
      • Fingernail scrapings/clippings.
      • Pubic hair: Combing prioritized over plucking; if plucking necessary, quality over fixed quantity.
      • Head hair: Combing prioritized over plucking; if plucking necessary, quality over fixed quantity.
      • Blood: Volume per laboratory requirements for DNA, toxicology, grouping, serology (HIV, VDRL, HBsAg).
      • Urine: Volume per laboratory requirements for pregnancy test, drugs.

Spermatozoa Detection Times (Approximate ranges - sperm DNA persists longer):

  • Vagina: Up to 72 hrs (motile: 6-12 hrs).
  • Cervix: Up to 5-7 days.
  • Anal/Rectum: Up to 24 hrs.

Sexual Assault Evidence Collection Kit Contents

Accused Examination & Scene Evidence - Suspect & Scene Scoops

  • Accused Examination (Ref: Sec 176 BNSS):
    • Purpose: Identify signs of recent coitus, injuries; collect biological samples.
    • Samples: Penile swabs (glans, corona, shaft, prepuce), pubic hair (combed & plucked based on case-specific requirements), clothing, fingernail scrapings, blood (for grouping, DNA, STIs), saliva.
  • Scene of Crime:
    • Crucial: Secure scene, restrict access.
    • Search: Systematic patterns (spiral, grid, strip, zone) with advanced documentation technologies.
    • Collect: Trace evidence (fibers, hair, seminal/salivary/blood stains), weapons, digital evidence.
    • Document: Detailed notes, photography, sketches (with measurements), 3D reconstruction protocols.

⭐ Clothing of victim & accused: Collect, air-dry if wet, package separately in paper bags. Prevents DNA degradation & cross-contamination.

Preservation, Packaging & Dispatch - Sample Safeguard Secrets

  • Core Principles:
    • While air-drying is common practice, wet evidence (especially documents in liquid) may need laboratory transport in current state for professional processing by forensic experts. Wet documents should remain unfolded for forensic document examiners.
    • Use breathable paper bags or envelopes for biological stains; tamper-evident bags are essential for secure storage and transport, maintaining evidence integrity from crime scene to courtroom through well-defined packaging procedures.
    • Package each item of evidence separately to prevent cross-contamination.
    • Label meticulously: case no., date, time, item description, exact source, collector's initials.
    • Seal all packages securely to ensure integrity and prevent tampering.
  • Preservatives Guide:
    • Blood:

      ⭐ Blood for DNA analysis should be preserved with EDTA, while blood for alcohol estimation requires Sodium Fluoride as a preservative.

    • Urine: Thymol, Toluene, or simple refrigeration.
    • Viscera (Toxicology): Saturated Saline Solution or Rectified Spirit (prevents putrefaction).
    • Viscera (Histopathology): 10% Formalin.
    • Products of Conception (POC): Preserve in normal saline if fresh (for histopathology), or as per specific lab protocol.
  • Chain of Custody: Maintain comprehensive documentation identifying and tracking evidence from collection through final disposition, including collection method and each individual with possession responsibility, ensuring courtroom evidence matches crime scene collection per BSA requirements.

High‑Yield Points - ⚡ Biggest Takeaways

  • Consent is paramount before examination and sample collection under BSA provisions.
  • Collect clothing carefully; air-dry wet stains before packaging per BNSS protocols.
  • Use separate sterile swabs for vaginal, cervical, anal, and oral sites.
  • Semen detection: Acid Phosphatase (presumptive) and P30 tests (confirmatory); DNA profiling for definitive identification.
  • Collect pubic hair (combed and plucked), head, and other body hair.
  • Blood for DNA/grouping/toxicology; urine for drug screening.
  • Maintain strict chain of custody for all evidence per BNSS requirements.

Practice Questions: Collection of Biological Evidence

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On request of a police officer, a medical examination of an arrested person's body can be done by a registered medical practitioner, as per the following provision in the Code of Criminal Procedure -

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Flashcards: Collection of Biological Evidence

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_____ assay is used to test a glycoprotein present in semen, blood and urine of a male

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_____ assay is used to test a glycoprotein present in semen, blood and urine of a male

P30

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