Amy Archer Gilligan is believed to have killed at least 60 people in the rest home she owned between 1907 and 1917, with 48 of those occurring in the 5-year period between 1911 and 1916. Due to the nature of the industry, however, it was some years before local investigators began to ask serious questions about the exorbitantly high death rate coming from the Archer Home...Little did they know, she was becoming one of the most prolific serial killers in American history.