Charles Cullen was supposed to keep patients alive. Instead, he became one of America’s most prolific serial killers. In Part 1 of this two-part series, Marina’s sister Lisa is back by popular demand to tell the story of Cullen’s troubled early life, his path into nursing, and the suspicious deaths that followed him from hospital to hospital. By the time Somerset Medical Center started questioning his use of the Pyxis machine, the true scope of the horror is only starting to come into focus.

In December of 2021, police in Manchester, New Hampshire made a stunning announcement: a little girl named Harmony Montgomery was missing and no one had seen her for more than two years. Her father, Adam Montgomery, who had recently fought to obtain custody of her, claimed that she was with her biological mother, but police knew that wasn’t true. Where was Harmony? It was Adam’s estranged wife, Kayla Montgomery, who filled in the gaps for authorities that shifted the case from a disappearance to a murder investigation.

When Betsy Faria was found stabbed to death in her Missouri home, suspicion quickly fell on her husband, Russ. He had an alibi. He had no blood on him. But none of that seemed to matter. As police built their case, another figure stayed quietly in the background: Pam Hupp—Betsy’s friend, the last person to see her alive, and the unexpected beneficiary of her life insurance policy. In this episode, we follow the case from wrongful conviction to the slow unraveling of a story that was never as simple as it first seemed.