Miami-Dade Circuit Judge Stanford Blake imposed the sentence after rejecting defense claims that a four-year statute of limitations had expired on Connolly's second-degree murder conviction in the killing of 45-year-old John Callahan. Blake said a motion on that issue was filed past a 10-day deadline but was probably legally correct - meaning an appeal is certain.
Trial testimony showed Connolly provided information to Boston mobsters leading to Callahan's slaying. Connolly, 68, showed no emotion when the sentence was announced.
Connolly is already serving a 10-year federal prison sentence for his corrupt dealings with Boston's Winter Hill Gang. Blake said the state murder sentence will run consecutively to the federal term, which is set to end in 2011.
Callahan was fatally shot July 31, 1982, by, who has admitted the killing. Callahan's body was stuffed into the trunk of his Cadillac and discovered a few days later at a Miami International Airport parking lot.
Martorano and other Winter Hill figures testified that Connolly regularly tipped them off to potential "rats" or snitches within their own ranks, sometimes leading to their untimely demise. In Callahan's case, Connolly supposedly said the former World Jai-Alai president would probably implicate the mobsters in the 1981 murder of an Oklahoma businessman who owned the gambling business.
In return for his tips, prosecutors said Connolly was given inside information by Winter Hill chieftains James "Whitey" Bulger and Stephen "The Rifleman" Flemmi that led to high-profile FBI takedowns of bosses in Boston's rival Italian-American Mafia. That made Connolly a highly decorated FBI star.
Blake said Thursday that Connolly had "tarnished the badge" through his corrupt dealings with mobsters.
"You left law enforcement. You forfeited that badge that so many people wear proudly," Blake said. "For an FBI agent to go to the dark side is a sad, sad day."
Connolly's defense focused on the difficult job of investigating organized crime, on how FBI agents are forced to deal with unsavory characters to win larger victories. Connolly did not testify at his trial but insisted at a subsequent hearing that he had nothing to do with the Callahan killing.
"I never have, and I never would, knowingly say anything that would cause harm to come to any human being," Connolly said Dec. 4.
While Flemmi and other Boston gangsters have admitted their roles in many murders and other crimes, Bulger remains a fugitive on the FBI's Ten Most Wanted list. Testimony indicated that he disappeared following a 1995 tip from then-retired Connolly that a grand jury was about to indict him on racketeering charges.
The Winter Hill saga was the loose basis for the 2006 Martin Scorsese film "The Departed," with Matt Damon in the crooked cop role and Jack Nicholson playing a Bulger-like Irish-American gangster.