Crime Scene Investigation and Evidence Types

Chain of Custody

The documented process that tracks the movement of evidence.

Crime Scene

The location where a crime occurred.

Evidence

Anything that can prove or disprove a fact in a case.

Locard's Exchange Principle

The idea that when two objects come into contact, they exchange materials.

Trace Evidence

Small pieces of material left at a crime scene (e.g., hair, fibers).

Testimonial Evidence

A witness's statement under oath.

Physical Evidence

Any material object related to a crime (e.g., weapons, fingerprints).

Arch

A fingerprint pattern with no delta, ridges enter one side and exit the other.

Loop

A fingerprint pattern where ridges enter and exit from the same side.

Whorl

A fingerprint pattern with at least one complete spiral.

Minutiae

Small ridge details used to match fingerprints.

AFIS (Automated Fingerprint Identification System)

A database used to match fingerprints.

DNA Profiling

Identifying a person using unique DNA sequences.

CODIS (Combined DNA Index System)

A database for storing DNA profiles.

Polymerase Chain Reaction (PCR)

A method to amplify small amounts of DNA.

Restriction Fragment Length Polymorphism (RFLP)

A technique for analyzing DNA variations.

Mitochondrial DNA

DNA inherited from the mother, useful for old or degraded samples.