FILE - This June 23, 2011 file booking photo provided by the U.S. Marshals Service shows James "Whitey" Bulger. A federal judge in Boston will hear arguments Wednesday, Feb. 13, 2013, on Bulger's claim that he was given immunity to commit crimes while he was an FBI informant. Bulger's lawyers want to use his immunity claim as a defense at his upcoming trial. (AP Photo/U.S. Marshals Service, File)
BOSTON (AP) — A federal prosecutor has told a Massachusetts judge that any immunity agreement reputed gangster James "Whitey" Bulger claims he had with the government would be "void as a matter of law" if it included murder.
Bulger's lawyer argued that only jurors, not a judge, should be allowed to decide if Bulger's immunity claim is valid.
Both sides presented arguments Wednesday to the judge scheduled to preside at Bulger's trial in June.
The former Winter Hill Gang leader is accused of participating in 19 murders.
He claims a federal prosecutor gave him immunity for crimes while he was providing the FBI information on local leaders of his gang's main rivals, the Mafia.
Federal prosecutors asked a judge to decide the issue before trial.
The judge didn't indicate when he would rule.