Forensic Medical and Biological Examination
Forensic Medical and Biological Examination
This domain tests examination of living persons, corpses, and biological traces, and the interpretation of medical and DNA evidence. Core areas are injury assessment, cause and time of death, sexual-offence examination, toxicology, and DNA identity testing.
Core rules
- Document chain of custody and sample integrity; biological material is easily contaminated.
- Distinguish identification from probability: a DNA profile match must be reported with a statistical basis, not as automatic proof of guilt.
- Medical records and history matter; pre-existing disease, treatment, and timing affect conclusions.
- Cause of death is medical; legal causation and intent are for the court.
- Use appropriate controls and accredited methods; record sample sites and preservation.
Worked example
A bloodstain from a scene is compared with a suspect reference sample. The expert extracts DNA, quantifies it, amplifies, and types it. If the profiles match, the report states the match probability in the population; if low-template or mixed, the conclusion may be limited. The reasoning separates the laboratory result from the legal inference.
Traps
- Treating a DNA match as conclusive proof of guilt.
- Ignoring contamination or poor storage.
- Confusing medical cause with legal responsibility.
- Overinterpreting injuries without clinical context.