BOSTON >> James “Whitey” Bulger called his racketeering trial a “sham” Friday as he revealed he would not testify in his own defense, a decision that prompted a cry of “coward!” from the widow of a man he is accused of killing.

The highly anticipated decision came after Bulger met with his lawyers behind closed doors for about 20 minutes.

After attorney J.W. Carney Jr. announced the decision, Judge Denise Casper asked Bulger if he had consulted with his lawyers and if he was making the decision voluntarily.

With the jury out of the room, Bulger told the judge his decision was made “involuntarily.”

“I feel that I’ve been choked off from having an opportunity to give an adequate defense,” he said. “My thing is, as far as I’m concerned, I didn’t get a fair trial, and this is a sham, and do what youse want with me. That’s it. That’s my final word.”

Bulger railed against the judge’s decision prohibiting his lawyers from using an immunity defense. Bulger has claimed he received immunity from a now-deceased federal prosecutor, Jeremiah O’Sullivan.

“For my protection of his life, in return, he promised to give me immunity,” Bulger told the judge.

Casper ruled before trial that the supposed immunity was not a legal defense to crimes including murder.

“I understand, sir, if you disagree with it,” Casper replied.

Family members of Bulger’s alleged murder victims looked dejected over his decision not to take the stand. Patricia Donahue, the widow of one alleged victim, yelled “you’re a coward!” while Bulger was speaking.

“If you think you had an unfair trial, then get up there and tell all,” she said outside the courtroom afterward. “I am so disappointed in this whole trial. I thought that at least he would be man enough to get up there.”

Bulger, 83, is on trial in a broad racketeering indictment that accuses him of participating in 19 murders in the 1970s and ’80s as leader of the Winter Hill Gang. He has pleaded not guilty.

He fled Boston in 1994 and was one of the nation’s most wanted fugitives until he was captured in Santa Monica, Calif., in 2011.

O’Sullivan, who died in 2009, headed the New England Organized Crime Strike Force and was known for his aggressive pursuit of cases against local Mafia leaders, Bulger’s rivals.

Outside the courthouse, Carney said Bulger was describing an agreement he claims he had with O’Sullivan under which “in return for assuring that Jeremiah O’Sullivan would not be killed, O’Sullivan promised him that he would not be prosecuted for as long as O’Sullivan was head of the strike force.”

Carney did not elaborate, but Bulger seemed to be implying that O’Sullivan’s life was in danger because of his pursuit of the Mafia.

After Bulger made his remarks, the defense rested its case.

Prosecutors and Bulger’s lawyers are scheduled to make their closing arguments to the jury Monday. The jury is expected to begin deliberations Tuesday.

Earlier Friday, former Bulger hit man John Martorano was called as a witness by Bulger’s lawyers. Martorano had spent days on the witness stand earlier in the trial, describing what he said was Bulger’s role in a string of murders, including some he orchestrated, others he helped with and some he committed himself.

Bulger’s lawyers called Martorano to challenge testimony by Bulger’s former partner, Stephen “The Rifleman” Flemmi, about the killing of Flemmi’s girlfriend Debra Davis.

Flemmi had said he watched as Bulger strangled Davis.

When pressed by Bulger’s attorney Friday, Martorano acknowledged that Flemmi had once told him he killed Davis.

“He said it was an accident — he strangled her,” Martorano said, describing a telephone call he had with Flemmi in 1981 after Davis disappeared. At the time, Martorano was a fugitive hiding in Florida.

Carney asked Martorano if he asked Flemmi how strangling someone could be accidental.

“Is it fair to say he never went into any further details about it?” Carney asked.

“Correct,” Martorano said.

Earlier Friday, Carney said Bulger wants the $822,000 in cash seized from his Santa Monica apartment to go to relatives of victims who won monetary judgments in lawsuits but then saw those awards overturned by a federal appeals court because the statute of limitations had expired.

It appears that two families fall into that category: Relatives of Michael Donahue and Edward “Brian” Halloran. In 2011, the 1st U.S. Circuit Court of Appeals upheld an earlier decision that ruled the two families didn’t file their lawsuits against the FBI in time.

Other victims’ families have had their lawsuits tossed before trial and some have won judgments against the government, but Carney specifically cited those whose judgments were thrown out by the 1st Circuit.

Bulger is accused of fatally shooting Halloran, a Bulger associate, and Donahue, an innocent bystander who had offered Halloran a ride home in May 1982.

Prosecutor Brian Kelly said it has always been the government’s intention to give Bulger’s seized assets to victims’ families, but he said he isn’t sure Bulger “can dictate which ones” get the assets.

If he’s convicted, Bulger would have to give up his assets anyway. It is routine for the government to seek forfeiture of assets acquired through illegal activities.