It remains one of the most enduring mysteries in gangland lore: in 1941, while Abe Reles and three other key informants were under round-the-clock NYPD protection, the ruthless and powerful thug took a deadly plunge from the window of a Coney Island hotel. The first criminal of his stature to break the underworld’s code of silence, he had begun "singing” for the courts—giving devastating testimony that implicated former cronies—with more to come. With cops around him day and night, how could Abe have gone out the window? Did he try to escape? Did a hit man break in? Or did someone in the "squealer’s suite” murder him? Here’s the gripping story, packed with political machinations, legal sleight-of-hand, mob violence—and, finally, a proposed answer to the question: How did Abe Reles really die?  Murder mysteries:Why didn’t police investigate the mysterious sounds they heard on the night that Reles died? Why did the lead investigator fail to gather crucial evidence at the hotel—or follow police procedure for interviewing witnesses and securing the crime scene?  What do previously classified FBI documents reveal about Brooklyn DA William O’Dwyer, who had plans to run for mayor of New York?  Why was the note "Withhold information by order of D.A.” scribbled on Reles’s autopsy report?  Why was Abe’s widow so bitterly opposed to reopening the case? Why doesn’t the official story add up?