BOSTON — As lawyers for James "Whitey" Bulger begin to defend him against a massive racketeering indictment charging him in 19 killings, one big question remains: Will he testify?

Some lawyers not connected to the case say Bulger has too much baggage to testify, including a prior criminal record and a long reputation as an organized crime figure.

But others say Bulger's case is different because, at age 83, he knows he is likely to spend the rest of his life in prison and may be more interested in settling scores than being acquitted.

Bulger said as much in letters he wrote to a friend from prison after he was captured in Santa Monica, Calif., following 16 years on the run as one of the nation's most-wanted fugitives.

Bulger told his friend he wanted to set the record straight on two fronts: First, he was not an FBI informant, as prosecutors and many witnesses at the trial have claimed, and second, he did not kill women, according to a book called "Whitey Bulger: America's Most Wanted Gangster and the Manhunt That Brought Him to Justice" written by Boston Globe reporters Shelley Murphy and Kevin Cullen.

"This whole trial is an effort on his part to overcompensate for his informant label," said Boston attorney Anthony Cardinale, who helped expose the corrupt relationship between the FBI and Bulger while he represented former New England Mob boss Francis "Cadillac Frank" Salemme.

"He's doing anything he can to have some shred of a reputation left," Cardinale said.

But despite the impulse to want to rebut testimony that he ratted on the Mafia and members of his own gang, Bulger would open himself up to even more damaging evidence if he decides to take the witness stand, Cardinale said. He said prosecutors could then bring in evidence that when he was charged in a string of bank robberies in the 1950s, he ratted out his co-defendants in that case.

"He would be a grease spot on the floor after cross-examination," Cardinale said.

In the months before the trial, Bulger's lawyers said he was eager to testify to support his claim that he received immunity from crimes from a former federal prosecutor. But after Judge Denise Casper ruled that Bulger couldn't use that as a defense, his lawyers sidestepped the questions about his possible testimony.

On Friday, when the judge asked attorney J.W. Carney Jr. if Bulger might testify, he said only that he would let her know after his other witnesses testify.

Late Sunday, Bulger's attorneys filed a motion to have the jury sequestered when they begin deliberations.

The Boston Globe reported that the five-page motion urged Casper to sequester the jury and keep them away from media coverage because of the "extremely prejudicial" way the news media has written about Bulger, including some Globe columns.

U.S. Attorney Carmen Ortiz's office had not filed a response to the request, the newspaper said.

The first defense witnesses will be called Monday.

During the prosecution's case, Bulger's lawyers have spent a great deal of time trying to knock down the informant claim by suggesting that Bulger's FBI handler, retired Special Agent John Connolly Jr., attributed information from other informants to Bulger in an attempt to advance his own career. At the time, bringing down the Mafia was a national priority for the Justice Department, and Connolly's recruitment of top-echelon informants against the group won him numerous accolades. Connolly is now in prison.

Bulger, through his lawyers, has vehemently denied being an informant. Carney told the jury that it went against Bulger's Irish heritage to be an informant and that Bulger loathed anyone who ratted on friends or enemies.

So it would not be a complete surprise if Bulger wanted the jury to hear that from his own mouth.

During their opening statements, Bulger's lawyers acknowledged he ran a lucrative criminal enterprise that took in millions through illegal gambling, extortion and drug trafficking.

Boston attorney Martin Weinberg said because Bulger's lawyers have admitted to some charges, he is likely to be convicted of enough counts to keep him in prison for the rest of his life.

"He's going to have a narrower set of objectives," Weinberg said.

"It makes it more likely for him to testify if his objectives are something other than a complete acquittal because he can admit to things that other defendants couldn't and attempt to persuade a jury that, 'You heard what I admitted to, please respect those specific areas as to which I deny guilt.'"

But Bulger runs a high risk of prosecutors bringing in more damaging evidence if he testifies.

"He might insist that he wasn't a rat, he wasn't an informant. ... But is it worth it for him to hold his head high and say, 'I wasn't an informant for the government, or I never killed women' when he will be forced to admit other things on the stand?" said Boston College law professor Michael Cassidy.

Ultimately, the decision will be up to Bulger.

Cassidy said Bulger could decide to testify simply to deny claims made by three once-loyal cohorts who became government witnesses and testified against him.

"He has to sit and listen to them without telling his version of the story," Cassidy said. "Maybe he just insists on (testifying). 'You know, I'm going to jail for the next 10 years anyway, I'm going to die in prison. At least I'm going to have my time on the stand.' That's his right."