Exchange Principle
Definition
Locard's core idea that physical contact between two surfaces moves material in both directions, so a perpetrator both deposits and removes trace material at a scene.
Related terms
- Persistence
- The property that friction ridge configuration remains stable from birth through death and into decomposition, as long as the papillary dermis survives....
- Primary Transfer
- The direct movement of biological material from an animal to a surface it contacts. When a dog sheds hair onto its owner's...
- Secondary Transfer
- The movement of a glass fragment from a primary surface (which contacted the broken glass) to a secondary surface (which contacted the...
- TPR Framework
- Transfer, persistence, recovery: the three sequential filters that every trace passes through, and the lens analysts use to weigh what a positive...
- Trace Evidence
- Small quantities of material transferred between people, objects, and locations during contact. Forensic geology focuses on the geological subset of trace evidence:...
Explained in
- Locard's Exchange Principle and Trace TransferLocard's core idea that physical contact between two surfaces moves material in both directions, so a perpetrator both deposits and removes trace material at a...