Boston gangster James "Whitey" Bulger's lawyers have asked an appeals court to overturn his racketeering conviction, saying his trial was unfair.
One of Bulger's lawyers argued before the 1st US Circuit Court of Appeals that his client's right to a fair trial was violated when he was barred from testifying about his claim that he received immunity from a federal prosecutor.
He also argued that prosecutors did not turn over information about certain details of an agreement he says they had with a hit man who was a key witness against Bulger.
A prosecutor told the three-judge panel the trial judge correctly ruled that Bulger had not presented hard evidence of an immunity agreement and should not be allowed to testify about it.
Bulger was not present.
The court did not immediately rule.