An extraordinary tale of modern science and old-fashioned gumshoe work applied to a world-renowned crime 80 years after the fact.On Aug. 4, 1944, a German "Jew-hunting unit" searched an Amsterdam warehouse and discovered the family of young Anne Frank in a hidden apartment. The Franks had been sheltering there for more than two years, shielded by paterfamilias Otto's workers. He alone survived the death camps. Hauntingly, as Sullivan writes, the last sighting of Anne was at Auschwitz, where, "delirious with typhus," she was "naked except for a blanket covering her shoulders." The officer who led that German squad wound up as an inspector in the Austrian police, while Otto spent his life overseeing Anne's memory through the publication of her diary. But who exposed the Franks' hiding place to the Nazis? That was the question some 50 data scientists, historians, forensic scientists, and other researchers, mostly Dutch, had before them, and it's the overarching question of this book. With the aid of retired FBI special agent Vince Pankoke, the team used artificial intelligence, behavioral psychology, and other modern methods to find out, examining numerous possible suspects. Only one met the familiar categories of knowledge, motive, and opportunity. The investigative team determined that he was a Jewish notary who used the Franks' sanctum as a bargaining chip to save his own family. On returning to Amsterdam, Otto received an anonymous note revealing his betrayer's identity. He did not broadcast it because, the investigators conclude, Frank may have recognized the man's desperate situation as he made that fateful decision to collaborate. Sullivan's narrative, full of twists and turns and dead-end leads, commands attention at every page, dramatic without being sensational. She writes, memorably, of Otto's work after the death of their Judas: "He wanted [everyone] to know that fascism builds slowly and then one day it is an iron wall that looms and cannot be circumvented."Every reader of Anne Frank's Diary will want to have this superbly rendered tale of scholarly detection at hand.

An extraordinary tale of modern science and old-fashioned gumshoe work applied to a world-renowned crime 80 years after the fact.On Aug. 4, 1944, a German "Jew-hunting unit" searched an Amsterdam warehouse and discovered the family of young Anne Frank in a hidden apartment. The Franks had been sheltering there for more than two years, shielded by paterfamilias Otto's workers. He alone survived the death camps. Hauntingly, as Sullivan writes, the last sighting of Anne was at Auschwitz, where, "delirious with typhus," she was "naked except for a blanket covering her shoulders." The officer who led that German squad wound up as an inspector in the Austrian police, while Otto spent his life overseeing Anne's memory through the publication of her diary. But who exposed the Franks' hiding place to the Nazis? That was the question some 50 data scientists, historians, forensic scientists, and other researchers, mostly Dutch, had before them, and it's the overarching question of this book. With the aid of retired FBI special agent Vince Pankoke, the team used artificial intelligence, behavioral psychology, and other modern methods to find out, examining numerous possible suspects. Only one met the familiar categories of knowledge, motive, and opportunity. The investigative team determined that he was a Jewish notary who used the Franks' sanctum as a bargaining chip to save his own family. On returning to Amsterdam, Otto received an anonymous note revealing his betrayer's identity. He did not broadcast it because, the investigators conclude, Frank may have recognized the man's desperate situation as he made that fateful decision to collaborate. Sullivan's narrative, full of twists and turns and dead-end leads, commands attention at every page, dramatic without being sensational. She writes, memorably, of Otto's work after the death of their Judas: "He wanted [everyone] to know that fascism builds slowly and then one day it is an iron wall that looms and cannot be circumvented."Every reader of Anne Frank's Diary will want to have this superbly rendered tale of scholarly detection at hand.