1. Physical evidence like fingerprints, firearms, trace evidence, and biological evidence can be used to identify suspects and link them to crimes. This evidence is collected using techniques like dusting for fingerprints, and DNA testing of biological samples. 2. Once collected, evidence is examined using specialized equipment like microscopes, chemicals, and DNA testing to analyze samples and identify their characteristics. 3. Evidence can provide critical information to investigations by identifying suspects and objects, reconstructing crimes, and exonerating the innocent when analyzed properly. Contamination issues need to be avoided during the collection and examination of evidence.