Fred Weichel has spent more than three decades in prison in the fatal shooting of Robert LaMonica.
In 2004, a judge granted Weichel's request for a new trial after his lawyers produced a letter in which a friend of Weichel's, Thomas Barrett, confessed to killing LaMonica. The letter was written to Weichel's mother in 1982. The state's highest court reversed that ruling in 2006, finding that Barrett's purported confession lacked trustworthiness and was not sufficiently corroborated.
Weichel's lawyers have argued previously that three of Bulger's former associates claim that Bulger helped frame Weichel for LaMonica's killing by urging a former FBI agent not to tell authorities that he saw Weichel at a Boston bar shortly before LaMonica was fatally shot in the suburb of Braintree.
In letters he wrote last fall from the Plymouth County House of Correction, Bulger claims that a friend of Weichel's once told him he was afraid because he had beaten up a man in a fight and the man's friend - LaMonica - was promising retribution.
"I told him get him first, kill him ... if you don't get him first I'd say he will get you - he's dangerous - so again kill him and it's over," Bulger wrote. He said he also warned the man never to repeat their conversation.
Bulger did not reveal the man's name, but he wrote that he hopes "he would be brave enough to come forth" now.
The handwritten letters are transcribed in documents sent Friday to Norfolk Superior Court, where Weichel's motion for a new trial is filed.
Weichel's lawyer, Michael Ricciuti, acknowledged that the letters are difficult to discern because in some places, they appear to be written in code. Even though Bulger does not identify the man, Ricciuti believes Bulger is referring to Barrett.
"We believe that the letters mean that Bulger encouraged Barrett to kill the victim (LaMonica), that Bulger warned Barrett not to talk about their conversation ever again, and that Bulger is encouraging Barrett to come forward because Weichel is innocent," Ricciuti said Monday.
He said the letters were written by Bulger to a supporter of Weichel's, but he would not identify the supporter.
David Traub, a spokesman for Norfolk District Attorney Michael Morrissey, declined to comment, saying prosecutors have not yet seen the documents.
Bulger, 84, is serving two life sentences after being convicted of playing a role in 11 murders and a string of other crimes in the 1970s and '80s.
Prosecutors have said Weichel and LaMonica had an ongoing feud. They say a teenager was unequivocal when he identified Weichel as the shooter.
