The prison murder of John Joseph Saupp, an inconsequential forger and mail robber, was, according to U.S. Attorney General Robert F. Kennedy, the "biggest single intelligence breakthrough yet in combating organized crime and racketeering in the United States."
Saupp's fatal misfortune was his striking resemblance to Joseph (Joe Beck) DiPalermo, a syndicate hoodlum and Atlanta prison associate of crime leader Vito Genovese. Genovese had decided that another prisoner, minor crime figure Joseph Valachi (who was doing time for a narcotics offense), had turned stool pigeon.
He passed the death sentence on Valachi, and only by luck did Valachi survive three attempts on his life. Then Genovese, who was Valachi's cellmate, gave him the "kiss of death," indicating to Valachi that the campaign to kill him would continue and that he was doomed.
Valachi tried to be extra careful, waiting for the fourth attempt. He strongly suspected that among those out to execute the murder assignment was Joe Beck. On June 22, 1962, Valachi found himself surrounded by a group of prisoners, three of whom he suspected of being would-be killers. Just then another prisoner walked by him. Valachi, thinking it was Joe Beck trying to get behind him, seized a length of pipe from some nearby construction work and attacked his nemesis, banging him over the head.
Only after Valachi was taken to the associate warden's office did he discover he had fatally wounded the wrong man, that the victim was Saupp, a man he didn't even know. Saupp died about 48 hours later.
Valachi was now doubly on the spot. Mob leader Genovese still wanted him dead, and the authorities now had him on a murder charge. The only way out for Valachi was to turn federal informer. He did, and in his celebrated public testimony before Senator John McClellan's Permanent Subcommittee on Investigations, he revealed more secrets about organized crime than any witness up until that time.
John Joseph Saupp is chiefly remembered as the hapless catalyst who brought about Valachi's testimony. On his murder, Valachi, a longtime mob hit man, said, "You can imagine my embarrassment when I killed the wrong guy."