How is evidence collected and preserved at a crime scene?

In the USA, evidence at a crime scene is collected and preserved using a meticulous process. Forensic experts utilize gloves, tweezers, and evidence bags to avoid contamination. They document the scene through notes, sketches, and photographs, then collect physical evidence such as hair, fibers, and DNA samples. These items are carefully packaged, sealed, and labeled to maintain their integrity. Preserving the chain of custody ensures that evidence admissible in court. Finally, the evidence is stored in secure facilities to prevent degradation. This thorough process ensures that evidence is accurately collected and preserved for forensic analysis.