Unit 2 - Types of Evidence

something that tends to establish or disprove a fact; can include documents, testimony, or other objects

what is said in court by a competent witness; also called direct evidence or “prima facie” evidence

tangible items that tend to prove some material fact; also called real evidence

Evidence that is temporary; can be easily changed or lost (odors, temperatures, footprints, etc.)

evidence produced by a specific action or even at the scene that must also be observed and recorded (postion of objects, doors or windows open/closed or locked/unlocked)

evidence providing only a basis for inference about the disputed fact

evidence based on suggestion rather than personal knowledge or observation

material that has been collected from a known location but is of unknown origin

material that comes from a proven or known source

generally refers to a material that is expected to respond in a particular way in testing; often used to validate the method of testing by comparing test results to those of the questioned and known samples

material that can be related to a single source; always involves a comparison

material that can be associated only with a group of items that share properties or characteristics

• Nature of the offense and situation • Age or mental/physical state of the witness • Length of time between the offense and the testimony • Interviewing techniques • Witness’s prior relationship with the accused • Any earlier identification of other suspects by the witness

evidence produced by direct contact between a person and an object or between two objects

evidence produced by contact between person(s) and object(s), or between person(s) and person(s)

something that may associate a victim or suspect with a scene or with each other; e.g., personal belongings

• Recognition • Preservation • Identification • Comparison • Individualization • Interpretation • Reconstruction