Station 6 — Forensic Examination in Sexual Offences: Examination, Sampling and Preservation of Evidence
🎯 Candidate Task
Describe how you would obtain consent, examine a victim presenting after an alleged sexual offence, collect appropriate forensic samples and preserve the evidence. Also describe the modifications required when the alleged assault involves the anal region.
⚡ Model Station Answer
- Consent: I would explain the examination and evidence collection, obtain voluntary informed consent for each component, maintain privacy and allow the patient to decline any part.
- Examination: I would perform a respectful general examination, document relevant injuries and undertake an anogenital examination only with consent and appropriate assistance/chaperoning.
- Sampling: Samples would be selected according to the history and local forensic protocol, using separate sterile collection materials for each site.
- Preservation: Every specimen would be correctly dried or preserved as appropriate, separately packaged, labelled, sealed and documented to maintain chain of custody.
- Anal assault: I would inspect and document the perianal/anorectal region and obtain appropriate perianal and anal samples according to the history and protocol.
🔎 How to Perform / Approach
- Step 1 — Establish safety, privacy and consent.
Introduce yourself, ensure privacy, explain the purpose and components of examination and sampling, and obtain informed voluntary consent for each stage. - Step 2 — Take a focused history.
Record the relevant history needed to guide examination and sampling without repeatedly or unnecessarily questioning the patient. - Step 3 — Perform the general examination.
Examine systematically for relevant injuries and document their site, type and appearance accurately using appropriate notes or body diagrams. - Step 4 — Perform the relevant anogenital examination.
With specific consent, adequate privacy, appropriate positioning and a chaperone where appropriate, inspect the relevant genital/perineal areas and document findings objectively without speculating about their cause. - Step 5 — Collect directed forensic samples.
Depending on the history and protocol, obtain appropriate swabs and other specimens from relevant sites and collect clothing, nail or biological specimens when indicated. Use separate sterile equipment for each sample. - Step 6 — Adapt for alleged anal sexual assault.
Inspect the perianal region and, when indicated and consented to, examine the anorectal area; obtain separate perianal and anal-canal samples according to the forensic protocol. - Step 7 — Package and preserve correctly.
Air-dry swabs when required, package individual biological evidence separately in appropriate containers, label each specimen accurately and avoid cross-contamination. - Step 8 — Seal and maintain chain of custody.
Apply the appropriate evidence seal, record collection details, date/sign as required and document every transfer of the specimen to preserve its integrity.
📝 Important Viva Questions
1. Can a sexual-assault examination be performed without the patient’s consent?
Answer: In a competent patient, informed voluntary consent is required. Consent should be obtained separately for relevant components of examination and evidence collection.
2. Why are forensic specimens collected and packaged separately?
Answer: Separate collection and packaging reduce cross-contamination and help preserve the identity and evidential integrity of each specimen.
3. What samples may be relevant after alleged anal sexual assault?
Answer: Depending on the history and local protocol, separate perianal and anal-canal swabs and other relevant biological or clothing specimens may be collected.
4. What is meant by chain of custody?
Answer: It is the documented record showing collection, sealing, handling, transfer and custody of evidence from the time it is obtained until it reaches the authorized recipient.
5. How should forensic examination findings be documented?
Answer: Findings should be recorded accurately, objectively and systematically, describing what is observed without making unsupported assumptions about how an injury occurred.