Based on Reles's accounts to assistant DA Turkus, Lepke was implicated in several murders. He hid out in Brooklyn while his businesses went to hell. He was approached by three "friends" (allegedly Anastasia, Zwillman and Lansky) and advised to surrender on a Federal narcotics rap. Supposedly he'd serve "only" ~six years, which would keep him out of the clutches of Thomas E. Dewey, crime-busting New York prosecutor, who had him on the murder raps. Lepke in fact got 15 years in Leavenworth.

Meanwhile, the Presidential election of 1940 was looming. GOP power-to-be Dewey (who was the GOP candidate in '44 and '48) accused President Roosevelt of "sheltering" Lepke from the NY State murder rap because Lepke got tribute from Sidney Hillman, a Garment District union chief who was FDR's closest labor adviser. FDR was forced to cooperate with Dewey, who then nailed him on the murder rap.

BTW: Lepke was so big that the first Federal charge against him was a violation of the Sherman Antitrust Act--he so dominated the garment industry and trucking that he was charged with being a "combination in restraint of trade" like US Steel and Standard Oil a generation earlier.