Forensic Histopathology is a subspecialty of pathology used to investigate crime scenes and the corpses of people who have died suddenly or of suspicious or unknown causes. It incorporates anatomical pathology, histology, DNA technology, firearms examination, trace evidence, serology, and toxicology. It involves autopsies, also known as post-mortem examinations, and forensic analysis, to help determine the cause of death and circumstances. Investigation involves collection of DNA, blood and tissue samples, laboratory testing, stage of death analysis, medical history analysis, witness statements and any other documentation from the scene. Forensic Pathology assists law enforcement agencies and families, and also makes contributions to public health and preventative medicine by studying the dead.