Sexual Assault Investigation

Sexual Assault Investigation - Law & Order

• Definition (IPC 375): Rape includes penetration of penis into vagina, mouth, urethra, or anus; or object/any body part into vagina, urethra, or anus; or manipulation of body part to cause penetration; or application of mouth. Without consent or with consent obtained under fear, misconception, or from an unsound/intoxicated person, or person < 18 years.
• POCSO Act, 2012: Protection of Children from Sexual Offences Act. Deals with sexual offences against individuals < 18 years. Stricter punishments, child-friendly procedures.
• Consent (IPC 90): Not valid if given under fear of injury/death, misconception of fact, by person of unsound mind, intoxicated, or < 18 years.

⭐ IPC 376: Punishment for rape. Specific subsections (376A-E, DAB) detail punishments for aggravated forms, repeat offenders, gang rape, etc., including death penalty in certain cases (e.g., causing persistent vegetative state or death).

Sexual Assault Investigation - Victim Care & Clues

• Victim Care & Consent:
  • Prioritize medical & psychological well-being.
  • Informed consent (CrPC Sec 53A); minor: parental/guardian (POCSO Act).
  • History taking: verbatim, non-judgmental.
• Examination (As per CrPC Sec 164A):
  • General physical: note injuries, nutritional status.
  • Systemic examination.
  • Genito-anal: inspect for injuries, discharge. Use colposcope/toluidine blue for micro-trauma.
  • ⚠️ Two-finger test (TFT) is BANNED.
• Evidence Collection Protocol:
  • Clothing: air-dry if wet, pack separately.
  • Swabs: Oral, vaginal (high/low), cervical, anal, perineal, bite marks/stains.
  • Samples: Blood (DNA, STI, alcohol), urine (pregnancy, drugs).
  • Hair (combed & plucked), fingernail scrapings.
  • Documentation: notes, diagrams, photography (with consent). Chain of custody vital.

⭐ Spermatozoa persistence: Vagina up to 72 hrs (motile ~12 hrs), Cervix 5-7 days, Anus/Rectum 24-48 hrs.

Sexual Assault Investigation - Suspect Scrutiny

• Legal Considerations:
  • Arrest & legal rights (CrPC Sec 53, 53A, 54).
  • Consent for examination is crucial; if refused, proceed under legal provisions.
  • Examination by registered medical practitioner.
• Physical Examination:
  • Detailed general physical & genital examination.
  • Note signs of struggle: abrasions, bruises, bite marks (swab for DNA).
  • Look for trace evidence: victim's hair, fibers, or DNA on suspect.
• Sample Collection (within 24-48 hours ideally):
  • Blood: Grouping, DNA, alcohol, drugs.
  • Urine: Drugs.
  • Saliva: Secretor status, DNA.
  • Hair: Scalp & pubic (plucked with roots).
  • Nail clippings/scrapings.
  • Penile swabs: For semen, epithelial cells (if recent coitus alleged).
  • Clothing worn during alleged assault.

⭐ CrPC Section 53A mandates the examination of a person accused of rape by a registered medical practitioner, including collection of DNA samples, even without consent if reasonable grounds for belief of offence exist. This was a key amendment post-Nirbhaya case for strengthening evidence collection against the accused.

• Documentation: Detailed report with all findings, including negative ones (Potency, STIs).

Sexual Assault Investigation - Lab Sleuths & Reports

• Chain of Custody: Essential documentation trail; ensures evidence integrity and admissibility.
• Lab Analysis Workflow:

• Key Lab Investigations:
  • Semen ID:
    • Florence Test (Choline).
    • Barberio's Test (Spermine).
    • Acid Phosphatase (AP): > 50 IU/L = significant.
    • PSA/p30: Confirmatory (even if azoospermic).
  • Spermatozoa (Persistence):
    • Vagina: Motile ~6-12 hrs; Non-motile ~3-5 days.
    • Cervix: Non-motile ~7-10 days. Heads persist longer.
  • DNA Profiling: Links individuals to evidence.
  • STI Screen: HIV, HBV, HCV, Syphilis, Gonorrhea, Chlamydia. Offer PEP.
• Medico-Legal Report (MLR):
  • Objective findings, expert opinion. Documents chain of custody.

  ⭐ PSA (p30) is a key confirmatory test for semen, vital if sperm are absent (azoospermia/vasectomy).

High‑Yield Points - ⚡ Biggest Takeaways

• Consent is paramount; its absence defines sexual assault (IPC 375).
• Conduct medical examination promptly (ideally <72 hours); the Two-Finger Test is banned.
• Meticulous evidence collection (e.g., swabs, clothing) and strict chain of custody are vital.
• Semen detection (e.g., Acid Phosphatase test, presence of spermatozoa) is crucial.
• DNA profiling offers the most conclusive evidence for perpetrator identification.
• Detailed, objective documentation and empathetic psychological support for the survivor are essential.