BOSTON — James "Whitey" Bulger is on trial on a long list of charges, including participating in 19 killings. Here's a look at the case against him, his defense and what's happening in the courtroom:

THE HISTORY

The 83-year-old Bulger, the alleged former leader of the Winter Hill Gang, was one of the nation's most wanted fugitives after he fled Boston in 1994. He was captured in 2011 in Santa Monica, Calif., where he had been living with his longtime girlfriend in a rent-controlled apartment. His early image as a modern-day Robin Hood who gave Thanksgiving dinners to working-class neighbors and kept drug dealers out of his South Boston neighborhood was shattered when authorities started digging up bodies.

THE PROSECUTION

Prosecutors on Friday called two bookmakers who testified that they were forced to pay monthly "rent" or "tribute" payments to Bulger and his gang if they wanted to stay in business. James Katz said if bookies did not pay Bulger's gang, they could "wind up in the hospital." Richard O'Brien said he had been affiliated with the New England Mafia, but decided to operate independently after members of the mob were arrested. He said Bulger told him during a meeting, "If you want to be in business, you're with us."

THE DEFENSE

Katz acknowledged under questioning by Bulger attorney J.W. Carney Jr. that he made most of his payments to Bulger's partner, Stephen "The Rifleman" Flemmi, and that he only met Bulger once. The defense is due to cross-examine O'Brien on Monday.

THE JURY

Eleven men and seven women are serving on the jury, including 12 regular jurors and six alternates. The trial is expected to last three to four months.

BULGER

The defendant, usually stoic in court, chuckled after O'Brien testified that Bulger once threatened a man who wanted to go into business for himself by saying he had another business besides bookmaking: "Killing (expletive) like you."

WHAT'S UP NEXT

Hitman John Martorano is expected to testify Monday as one of the prosecution's star witnesses. Martorano admitted to killing 20 people and served 12 years in prison. Bulger's lawyers have attacked his credibility and the "extraordinary" deal he got from prosecutors in exchange for his cooperation.