Journalist’s dangerous obsession with a forgotten serial killer unraveled her reality

Laura Greenberg was a journalist determined to understand why people kill. In her search for answers, she befriended a long-forgotten serial killer behind bars. As he described his crimes, her sense of reality began to unravel.

Greenberg’s unsettling bond with Doug Gretzler — who, along with accomplice Willie Steelman, killed 17 people, including two children — continues to haunt her decades later. Her search for understanding is the focus of Oxygen’s new true-crime documentary, "Charmed...