Accused mob boss and serial killer James "Whitey" Bulger hopes to make an alleged grant of immunity from the federal government the focus of his upcoming trial. Today in federal court, Judge Richard Stearns heard dueling arguments on how Bulger's claims of immunity should play out — and asked the defense and prosecution to revisit the issue in two weeks.

Bulger, who allegedly murdered 19 individuals during his decades-long criminal career, claims he received an immunity deal from former U.S. Attorney Jeremiah O'Sullivan that should protect him from prosecution. At today's hearing, assistant U.S. Attorney Zachary Hafer argued that Judge Stearns should determine the validity of that claim before the trial begins — and that, whatever the specifics of Bulger's alleged deal, the notion that he was granted immunity for his alleged crimes is absurd. 

“As matter of law," Hafer argued, "a U.S. Attorney does not have right to authorize the killing of U.S. citizens.... Any contract between Mr. O'Sullivan and Mr. Bulger, to the extent that it contemplated murder, would be null and void as a matter of policy.”

But Bulger's attorney, J.W. Carney, vehemently disagreed. Carney said the question of whether Bulger's immunity claim is valid or not should be left to the trial jury. And he bristled at the prosecution's suggestion that the court can compel Bulger to lay out the details of that claim before the trial starts. 

"James Bulger," Carney said, "will testify that he was given immunity from prosecution by Jeremiah O'Sullivan. I suspect the government will have quite a few questions for Mr. Bulger.... To remove his defense of immunity from being presented to the jury would, in effect, deny him his right to a fair trial."

Stearns closed today's proceedings by asking Carney and Hafer to supplement their arguments at a follow-up hearing on February 27. 

Bulger's legal team has previously requested that Stearns — who worked for the U.S. Attorney's Office in Boston — recuse himself from this case. Stearns refused that request last year. 

Recent court filings show that Bulger, in a jailhouse conversation with his brother Jackie, disputed the widely accepted belief that he was an informant for the FBI. How Bulger's rejection of the "informant" label might undercut his claim of immunity went undiscussed in today's proceedings.