Updated

A former close associate of James "Whitey" Bulger offered gruesome details Tuesday of three killings he says he watched Bulger commit, including the choking of a woman.

Kevin Weeks described the killings during his second day of testimony in the reputed gangster's trial for allegedly participating in 19 murders in the 1970s and 1980s.

Bulger has pleaded not guilty, and his attorneys had not had a chance to cross-examine Weeks, a former enforcer in Bulger's Winter Hill Gang.

In the past, they've challenged his credibility and criticized the plea deal Weeks received from prosecutors in exchange for his testimony. Week served five years in prison for being an accessory in five murders and other crimes.

On Tuesday, Weeks said he was at a South Boston house with Bulger in 1985 when he heard a thud. He said he then saw Bulger choking 26-year-old Deborah Hussey, the stepdaughter of Bulger's partner, Stephen "The Rifleman" Flemmi.

Weeks said Flemmi then strangled her with a rope after he realized she was still alive.

Weeks also said Hussey and two other murder victims were buried in a basement but later moved. He said he led authorities to the bodies in 2000.

During testimony Monday, Bulger only occasionally glanced at his former right-hand man as Weeks described how Bulger opened fire on a car and killed two men in 1982.

Weeks testified that Bulger donned a wig and mustache, drove a souped-up "hit car" and pumped bullets into Edward "Brian" Halloran, whom he had heard was cooperating with authorities against him, and Michael Donahue, an innocent bystander who happened to offer Halloran a ride home that night.

Weeks said he saw Bulger pull up to the car Halloran got into as he left a restaurant in South Boston.

"He slid across the front seat and he yelled out, `Brian!' and he proceeded to start shooting," Weeks said.

When he called Bulger later that night, Bulger said he was eating dinner with his girlfriend and urged him to "go get something to eat," Weeks said.

Donahue's son Thomas, who has attended every day of the monthlong trial with his mother and two brothers, said hearing Weeks testify about the killing of his father had shaken his family.

"It tears you apart hearing the horrific story," he said.

Weeks, who was a close associate of Bulger's for two decades, later became a government witness and eventually led authorities to the bodies of people who were allegedly killed by Bulger and the gang.

Weeks said he first developed a friendship with Bulger in the 1970s while he was working as a bouncer at Triple O's, a South Boston bar where Bulger did business as the leader of the Winter Hill Gang. Soon, he said, he was working as an enforcer, driving around South Boston and picking up cash from local bookmakers Bulger and his gang were extorting.

"Sometimes I'd beat somebody up," he said.

Weeks said Bulger and his gang also extorted multiple businessmen and drug dealers for a cut of their profits.

Bulger, 83, was one of the nation's most wanted fugitives after he fled Boston in 1994. He was captured in 2011 in Santa Monica, Calif.