Crime Scene Notes

Trace evidence

Small measurable physical material left at a scene.

Locard’s Exchange Principle

Cross-transfer of evidence when individuals or objects come into contact.

Direct evidence

Firsthand observations or evidence.

Circumstantial evidence

Indirect evidence implying a fact but not proven directly.

Biological evidence

Examples include body fluids, hair, and plant parts.

Physical evidence

Examples include fingerprints, footprints, tool marks, bullets, and fibers.

Seven S’s of Crime-Scene Investigations

Steps include Securing, Separating witnesses, Scanning, Seeing, Sketching, Searching for evidence, and Securing evidence.

Evidence Log

Contains case number, item inventory, item description, suspect and victim names, date and time, and signatures of witnesses and person recovering evidence.

Chain of custody

Process involving evidence log, evidence placed in baggie, baggie sealing, person in charge signing, Evidence bag given to next person. After analysis, bag is resealed with new tape and new signature.