Answer - The pathologist begins the investigation by taking the patient history and is of utmost importance in determining cause of death. The scene investigation may disclose drugs or toxins, which may be related to the cause of death. Some poisonous agents are not detected on a routine drug screens; therefore the pathologist must have knowledge of medications and toxins in order to request the specific analytical tests needed to detect them. An example would include the "sniffing" of aerosol propellants, a risky activity that has been frequently reported in teenagers. Sniffing of propellant substances can cause sudden death by precipitating lethal cardiac arrhythmias.
A special analysis is required to detect the chemicals in the blood. In other cases, there may be sufficient natural disease to account for death, but the individual may in fact have died of a drug overdose or other subtle cause. In the case of drowning and suffocation, the autopsy findings may not be specific and police investigation may be critical to the understanding of the death. Data developed by coroners, medical examiners and pathologists is studied by medical epidemiologists and heath and safety agencies to develop strategies to prevent disease and injury, thereby saving lives. The data developed about motor vehicle injuries and fire deaths led to legislation requiring seat belts in vehicles and smoke detectors in building construction.
In the examination of skeletons or severely decomposed remains, the forensic pathologist needs a working knowledge of multiple methods of identification, including forensic anthropology, to establish identity. If sufficient skeletal parts remain, the pathologist may be able to determine the age, race and sex of the individual and sometimes estimate the length of time since death. Occasionally, specific markings on the bones may enable the pathologist to come to a conclusion as to the cause of death.