coroner (kôrˈənər) [key], judicial officer responsible for investigating deaths occurring through violence or under suspicious circumstances. The office has been traced to the late 12th cent. Originally the coroner's duties were primarily to maintain records of criminal justice and to take custody of all royal property. In England this second function persists in his jurisdiction over treasure-trove. In his present-day work of determining cause of death, the coroner proceeds by means of the inquest whenever there is doubt. In several of the United States the coroner has been replaced by the medical examiner, who can only conduct post-mortem examinations, and who works in cooperation with the public prosecutor.