US Marshall Wore Wire to Investigate Mob Witness Leak

A deputy U.S. marshal secretly wore a wire against a man who was like a father to him as part of the investigation into the leak of confidential witness information to the Chicago Outfit.

The details were revealed Tuesday in federal court as the deputy marshal, John Ambrose, battled prosecutors to get certain statements he allegedly made to investigators thrown out of his upcoming trial. Ambrose is charged with leaking information on a star witness, hitman Nick Calabrese -- information that made its way to mob boss James Marcello.

Federal agents focused on Ambrose as the source of the leak after listening to secret prison tape recordings of Marcello.

Ambrose was lured to FBI offices on a pretense in September 2006, then the feds revealed their evidence against him. The feds needed Ambrose to detail how the information got from him to Marcello. Ambrose answered the feds' questions but initially balked at wearing a wire, worrying he would be viewed as "a snitch," FBI Special Agent Ted McNamara testified.

Ambrose eventually recorded William Guide, a former Chicago Police officer who was convicted with Ambrose's cop father in the Marquette 10 scandal. Ambrose's father died in prison, and Guide became a second father to Ambrose.

The feds haven't charged Guide but claim in court filings Ambrose passed witness information to Guide, who allegedly has mob ties.

Thanks to Steve Warmbir