One notable case is the assistance offered by Greg Scarpa to the FBI in civil rights murders... possibly including the case now known as the "Mississippi Burning" killings.

He was a capo for the mafia in New York, but wound up in Mississippi in the 1960s helping the feds with some interrogations they couldn't do, using means they couldn't use.

That's basically exactly what it sounds like. He learned who the local Klan leader was (in the Mississippi Burning case, a TV salesman), grabbed him off the street and worked him over in a hotel room until the guy told Scarpa where the bodies had been dumped.

The feds never officially admitted that's what happened, but Scarpa has given details that match what's known about some cases, records of his work have turned up in related cases and his then-girlfriend (now widow), Linda Schiro, also testified about things she'd seen in a trip she took with him to Mississippi. And Scarpa's handler, Lindley DeVecchio, basically confirmed Scarpa's special talents in an interview on 60 Minutes.

Jerry Mitchell, a Clarion-Ledger reporter, thinks those details are off - that Scarpa was involved with another civil rights-murder investigation, but not the famous one.

Either way, a guy named The Grim Reaper was shipped down south to do some dirty, ugly things to some dirty, ugly people.

During the Second World War the Italian Mafia cooperated extensively with US navy intelligence in the war against fascist Italy. "Lucky Luciano" would help provide intelligence regarding the Italian community in New York. It was later agreed because of his help during wartime he would be released and immediately deported to Italy. Luciano also guaranteed using his influence that there would be no dock strikes in the docks he held influence in. His actual influence is disputed but the dockworker strikes stopped immediately after the deal was made.

The Italian Mafia were also instrumental in drawing up maps and finding Sicilians to dig up old photos of the coastline to help the invasion of Sicily. They were also used identify friendly Sicilian natives who would help the campaign.

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