Reinhold Kulle seemed like the perfect school employee. But in 1982, as his retirement neared, his long-concealed secret came to light. The chief custodian at Oak Park and River Forest High School outside Chicago had been a Nazi, a member of the SS, and a guard at a brutal slave labor camp during World War II. Similar revelations stunned communities across the country. As the Office of Special Investigations raced to uncover Hitler’s men in the United States, neighbors had to reconcile horrific accusations with the helpful, kind, and soft-spoken neighbors they thought they knew. Though Nazis loomed in the American consciousness as evil epitomized, in Oak Park—a Chicago suburb renowned for its liberalism—people rose to defend Kulle, a war criminal.