An external body examination of a decedent is essential at two stages in the forensic science process. The first time an external examination is carried out is upon discovery of a corpse. At this point, the body should be checked for visible signs of injury and those injuries that are most likely to have caused subsequent death. At this stage both the medicolegal death investigator or coroner and authorized police personnel are present, and the body is checked over in what is known as a preliminary external examination.