Locard's exchange principle underpins trace evidence analysis. In a murder case, the victim's jumper contains blue nylon fibres matching the suspect's car seat cover. The significance of this single fibre transfer is BEST interpreted as:
- A Definitive proof of contact between the victim and the suspect's car
- B Circumstantial evidence that the victim had contact with a surface sharing that fibre type; it supports but does not prove the association ✓
- C Of no evidential value without DNA extracted from the fibre
- D Inadmissible unless the fibre matches at the batch production level
Correct answer: B. Circumstantial evidence that the victim had contact with a surface sharing that fibre type; it supports but does not prove the association
Explanation
Locard's exchange principle states that every contact leaves a trace. Fibre evidence is evaluated using comparison microscopy and chemical/spectroscopic analysis (FTIR, Raman). A single fibre match provides circumstantial support for contact between two surfaces; however, fibre types are rarely unique and transfer can occur via secondary or tertiary pathways. The evidence is probabilistic and must be interpreted within the context of the full investigation — it is not definitive proof of contact but meaningfully corroborates other evidence.
Reference: The Essentials of Forensic Medicine and Toxicology (Narayan Reddy), 34th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.