BOSTON (AP) — A former top associate of fugitive mobster James "Whitey" Bulger coolly detailed Bulger's role in multiple murders as testimony began yesterday in wrongful death lawsuits brought against the FBI by families of three alleged victims.

The families of Deborah Hussey, Debra Davis and Louis Litif say the FBI is responsible for their deaths because it protected and failed to control Bulger and Stephen "The Rifleman" Flemmi, who were informants against the Mafia.

In opening statements, a Justice Department lawyer said the FBI did not know Bulger and Flemmi planned the killings and cannot be held liable in their deaths.

But lawyers for the victims' families said the FBI knew Bulger and Flemmi had committed multiple murders and it was foreseeable that they would kill others.

Mobster Kevin Weeks described in gruesome detail how Bulger and Flemmi killed Davis, who was Flemmi's girlfriend, and Hussey, who was the daughter of his common law wife, Marion Hussey.

Flemmi told investigators they killed Hussey in 1985 because she told her mother he had been molesting her.

Weeks said he watched as Bulger and Flemmi strangled the 26-year-old in a house in South Boston. He said he heard a thump as he came down the stairs and then saw Bulger choking Hussey.

After a few minutes, Bulger said the woman was dead. But Flemmi said she was still breathing and then put a clothesline around her neck, stuck a stick through it, and finished strangling her, Weeks said.

Weeks testified Bulger described how he and Flemmi killed Davis in 1981 because Flemmi believed the woman was going to leave him for another man.

Weeks said he was told by Bulger that Davis was taken to the basement, duct taped and strangled.

"She was leaving Stevie. That's why she was killed," he said.

Flemmi told investigators that Bulger worried that Davis would reveal what she knew about their relationship with the FBI.

Litif, a bookmaker who was also an FBI informant, was fatally shot in 1980. Litif's family alleges he was killed by Bulger, who was told by former FBI Agent John Connolly that Litif planned to cooperate with authorities against him.

Connolly was convicted in November of second-degree murder for leaking information to Bulger and Flemmi that led to the killing of gambling executive John Callahan. Connolly was sentenced to 40 years in prison.

Flemmi is serving a life sentence in 10 murders, while Bulger has been a fugitive since shortly before he was indicted in 1995 and is on the FBI's "Ten Most Wanted" list.