Physical or Trace Evidence
When physical evidence arrives in the laboratory, it is in a sealed plastic bag. Physical evidence refers to guns, knives, shirts with blood droplets, and even documents found at a crime scene. But the greatest technological advancements in forensic science over the past decade have occurred in the area of trace evidence. Trace evidence refers to very minute evidence like strands of hair, skin cells, blood specimens, or fingerprints. Equipment used to analyze this evidence includes high-powered electron microscopes, digital image processor, toxicology analyzers for drug testing, paint analyzers, and even the ability to cast shoe textures and imprints