Although autopsies can exclude other possibilities, they cannot conclusively prove whether a person drowned. As such, the investigation is of crucial importance in determining an accurate cause of death in potential drowning cases. Drowning is the fourth leading cause of accidental death in the United States, making it fairly likely that many police officers, particularly those in marine environments, will be responsible for investigating potential drowning deaths. The author describes the changes that occur to a body underwater and discusses how water conditions, such as temperature, depth, and currents, can affect submerged bodies. Considerations for investigators probing a suspected drowning are outlined and include the recommendation to observe various physical indicators on the victim, such as the presence of vomit around the mouth and blood pooling around the head and extremities of victims, which would indicate the victim was alive when they became submerged. Factors such as hand and arm positions, injuries and other marks, and level of decomposition can provide clues as to whether a victim drowned or was submersed in water following death. Finally, the use of new technologies to help locate drowning victims on the bottoms of lakes and rivers is described. Endnotes