BOSTON — James "Whitey" Bulger is on trial in a 32-count racketeering indictment accusing him of a long list of crimes, 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 called as a witness Monday ex-hit man James Martorano, one of three former Bulger cohorts who cooperated with the government and agreed to testify against in exchange for reduced sentences. Martorano, who admitted killing 20 people, spoke in a clipped, businesslike manner while describing how he pumped bullets into people and shot up cars, but said Bulger and partner Stephen "The Rifleman" Flemmi "sort of broke my heart" when he learned they had been FBI informants.

THE DEFENSE

Bulger's lawyers did not get a chance to cross-examine Martorano on Monday but are expected to attack his credibility. In opening statements, Bulger attorney J.W. Carney Jr. said prosecutors were so desperate for Martorano's testimony that they "basically put their hands up in the air and said take anything you want."

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 glanced over at Martorano as he took the witness stand, about 10 feet from where Bulger sits at the defense table.

WHAT'S UP NEXT

Martorano will continue testifying Tuesday. Once prosecutors finish their questioning of him, Bulger's lawyers will cross-examine him in what's expected to be a lengthy process.