Ex-FBI agent pleads guilty to perjuring himself during 'Whitey' Bulger trial
Former mob boss and fugitive James "Whitey" Bulger, who was arrested in Santa Monica, California on June 22, 2011, is seen in a combination of booking mug photos released to Reuters on August 1, 2011. REUTERS/U.S. Marshals Service/U.S. Department of Justice/Handout

A former FBI agent admitted on Monday that he lied on the witness stand during the 2013 trial of former Boston mob boss James "Whitey" Bulger, officials said.

Robert Fitzpatrick pleaded guilty to 12 criminal counts of perjury and obstruction of justice for a wide variety of false statements during the high-profile mob trial.

The first witness called by Bulger's attorneys, Fitzpatrick had told the jury he concluded that the Federal Bureau of Investigation should not be working with Bulger as an informant because when he looked into his eyes he "couldn't see his soul."

Fitzpatrick, now 76, also said he had been the first FBI agent on the scene of civil rights activist Martin Luther King Jr.'s assassination in 1968 and that he had later been sent to Boston on a special assignment to clean up "major problems" in that office.

On Monday, he admitted that all those statements were lies, federal prosecutors said in a statement.

His attorneys asked U.S. District Judge Dennis Saylor to sentence Fitzpatrick to two years of probation. Saylor will determine his sentence in August.

The trial cast a harsh light on the corrupt relationship between the Irish-American gangster and FBI agents who shared Bulger's heritage and turned a blind eye to his gang's murder and mayhem in exchange for information they could use against the Italian-American Mafia.

Fitzpatrick, who served in the FBI from 1965 through 1986, pleaded not guilty in his first court appearance on the perjury charges.

Bulger, 86, has denied serving as an informant, insisting he paid agents for tips but provided none of his own. He fled the city in 1995 on a tip from an FBI handler that arrest was imminent and was a fugitive for 16 years, most of them atop the FBI's "Ten Most Wanted" list. Agents caught up with him in an apartment in Santa Monica, California, in 2011.

He is serving a life sentence after being convicted of committing or ordering 11 murders while head of the Winter Hill gang in the 1970s and '80s.

The 2015 movie "Black Mass" told the story of Bulger's rise to power and eventual arrest.

(Reporting by Scott Malone; Editing by Frances Kerry and Dan Grebler)