The Angel of Death: Charles Cullen Charles Cullen was a nurse who worked at hospitals in New Jersey and Pennsylvania from the 1980s to early 2000s. On the surface, he looked professional—but secretly, he was one of the most prolific serial killers in medical history. Cullen injected patients with lethal doses of insulin and heart drugs, claiming he wanted to ease their pain. But many of his victims weren’t even terminally ill. Whenever suspicions arose, hospitals quietly let him go to avoid bad