Buccheri said Bulger told him to make arrangements to pay his partner, Stephen "The Rifleman" Flemmi, and he later gave Flemmi a check for the full amount.
Buccheri said the meeting took place at a cabana behind Flemmi's mother's house in South Boston. Years earlier, Buccheri had built the cabana at Flemmi's request. Flemmi testified that the gang kept a stockpile of guns in the cabana, in a space he cut into the wall.
During cross-examination, Bulger's lawyer Hank Brennan focused on Buccheri's long friendship with John Martorano, a convicted ex-hit man for Bulger, and James Martorano, his brother and a Bulger associate.
"I really didn't know what they did for a living," Buccheri said, after acknowledging that they were close friends and that he had contact with John Martorano while Martorano was a fugitive.
Assistant U.S. Attorney Brian Kelly followed up by asking Buccheri who put a gun in his mouth and who threatened his family — the Martoranos or Bulger.
"Mr. Bulger," he said.
Bulger, now 83, was one of the nation's most-wanted fugitives after fleeing Boston in late 1994 ahead of an indictment. He was finally captured in Santa Monica, Calif., in 2011.
Kelly told Judge Denise Casper that prosecutors plan to wrap up their case against Bulger following testimony from two more witnesses.
Bulger's lawyers will begin presenting their own witnesses immediately after the prosecution rests. On Thursday, the defense witness list was whittled down to a maximum of 16 after Bulger's lawyers said they no longer planned to call some people and Casper ruled that testimony from several others was irrelevant.
It is still unclear whether Bulger will take the stand in his own defense.