A forensic autopsy is a primary tool used to find answers to the cause of a person's death. A series of tests, involving external and internal examination of the body, using surgical techniques and a set of medical standards, offers specialists an opportunity to determine the presence of an injury and/or to identify a disease that may have contributed to or caused a death. A forensic pathologist, a medical doctor specially trained to recognize patterns of injury, collect evidence and investigate the circumstances surrounding a death, performs an autopsy. Small samples of each organ are taken for microscopic examination. Other tests that may be performed include studying genes and checking for drugs, chemicals, or toxic substances.