Forensics: Types of Evidence

Rules of Identification

1. If one or more qualities do not match then it is assumed that the evidence came from a different source. 2.If all qualities match it has the potential of being from the same source, but is not absolute.

Individual Characteristics

Evidence that can be associated to a common source with an extremely high degree of probability.

Class Characteristics

Evidence that can only be associated to a group.

Individual

Fingerprints, Bullet Striations, Footprints or tire prints, handwriting, fitting together broken objects

Reconstruction

Physical evidence is used to answer questions about: what took place? how was the victim killed? how many people were involved? what was the sequence of events?

Standard/Reference Sample

Physical evidence whose origin is known, such as a blood or hair from a suspect

Eyewitness

a police composite may be developed from the witness testimony by a computer program or forensic artist

Testimonial Evidence

a statement made under oath: also known as direct evidence or Prima Facie evidence.

Physical Evidence

any object or material that is relevant in a crime; also known as indirect evidence. ex. Hair, Fibers, Fingerprints, Drugs, etc.

Class

blood types, tiny shards of glass from a broken window, fibers from a sweater, carpet or car interior, paint chips

Identification of C.S. Evidence

the process of determining a substances physical or chemical qualities.