In 1980 in Toledo, Ohio—on one of the holiest days of the church calendar—the body of a nun was discovered in the sacristy of a hospital chapel. Seventy-one-year-old Sister Margaret Ann had been strangled and stabbed, her corpse arranged in a shameful and stomach-churning pose. But the police's most likely suspect was inexplicably released and the investigation was quietly buried. Despite damning evidence, Father Gerald Robinson went free. Twenty-three years later the priest's name resurfaced in connection with a bizarre case of satanic ritual and abuse. It prompted investigators to exhume the remains of the slain nun in search of the proof left behind that would indelibly mark Father Robinson as Sister Margaret Ann's killer: the sign of the Devil. When Satan Wore a Cross is a shocking true story of official cover-ups, madness, murder and lies—and of an unholy human monster who disguised himself in holy garb.