The Last Stone

On March 29, 1975, sisters Katherine and Sheila Lyons, ages ten and twelve, disappeared from a shopping mall in suburban Washington, DC. A massive police investigation yielded no results, and the case was shelved for decades. In 2013, a cold case squad detective discovered a lead that previous investigators had overlooked, pointing toward Lloyd Welch, then imprisoned for child molestation in Delaware. Mark Bowden, who had covered the original disappearance as a young reporter for a Baltimore newspaper, returns to document how five detectives pursued this new lead. Over months of intensive questioning and investigation into Welch's Appalachian family network, the detectives worked to distinguish truth from deliberate deception. The Last Stone chronicles their interrogation efforts and examines the mind of the suspect, revealing how skilled investigators approached the challenge of extracting truthful information from someone with strong incentives to lie.