Impression evidence refers to imprints left in material found at a crime scene that may link a defendant to a crime. Examples of impression evidence include:
Footprints in the dirt around a victim's home
Holes or cracks in walls caused by the blunt force of an object
Tire tracks in the sand near a crime scene
Forensics experts handle impression evidence carefully because it may easily deteriorate or wash away. They often create molds of the evidence to preserve them for use during an investigation. Attorneys may present impression evidence to a jury if it's relevant and could affect the outcome of a case.