James "Whitey" Bulger has asked the U.S. Supreme Court to hear his appeal of his racketeering convictions for playing a role in 11 murders and committing a litany of other crimes.

It is unclear if the high court will take up the Boston gangster's case. The court generally agrees to hear only a small percentage of the thousands of cases it's asked to review each year. The 1st U.S. Circuit Court of Appeals upheld Bulger's 2013 convictions in March.

A three-judge panel of the court found that Bulger had not shown that his right to a fair trial was violated when a judge barred him from testifying about his claim that a now-deceased federal prosecutor granted him immunity. The trial judge said Bulger had not offered any hard evidence that such an agreement existed.

Bulger, now 86, led a notoriously violent gang from the 1970s through the early 1990s. He fled Boston in 1994 after an FBI agent tipped him that he was about to be indicted. Bulger remained a fugitive until 2011, when he was captured in Santa Monica, California. He is now serving a life sentence.