When 9-year-old Elizabeth Olten vanished just a few hundred feet from home, her small Missouri town sprang into action—searching woods, knocking on doors, and hoping for the best. But the truth behind her disappearance would stun even seasoned investigators. In this episode, we walk through the heartbreaking case that raised difficult questions about justice, rehabilitation, and the capacity for violence in the very young.

When Somerset staff dug into Charles Cullen’s medication logs, the pieces finally started falling into place. In Part 2, Lisa takes us through the investigation that exposed Cullen’s pattern of quiet killings, the legal fallout, and the staggering number of lives he may have claimed—while hospitals looked the other way.

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.