A crusade to find a killer becomes a gripping, intensely personal investigation into a shocking cold case and the radicalization of a terrorist. "In September 2011, Erik Weissman and two friends were murdered in a brutal triple homicide in Waltham, Massachusetts. The case went unsolved for months and then years, with no discernible leads. Erik's friend Susan Zalkind, an investigative journalist, needed closure and knew that finding it would be up...