The Handbook of Forensic Services provides guidance and procedures for safe and efficient methods of collecting, preserving, packaging, and shipping evidence and describes the forensic examinations performed by the FBI's Laboratory Division. The successful investigation and prosecution of crimes require, in most cases, the collection, preservation, and forensic analysis of evidence. Forensic analysis of evidence is often crucial to determinations of guilt or innocence. The FBI has one of the largest and most comprehensive forensic laboratories in the world, and the FBI Laboratory is accredited by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board.