BOSTON — The widow of a man who prosecutors say was killed by James "Whitey" Bulger's gang testified Tuesday that after her husband disappeared in 1975, Bulger told her that he "was probably in Canada robbing banks."

The body of Tommy King, a former rival who had joined forces with Bulger, was found 25 years later, buried in a shallow grave along the Neponset River in Quincy.

Margaret King said Boston police officers came to her house on Nov. 6, 1975, looking for her husband. She said police told her that a man her husband had grown up with — Francis "Buddy" Leonard — had been found dead in her husband's car. She said she never saw her husband again.

King and relatives of others allegedly killed by Bulger and his gang were called to the stand by prosecutors Tuesday in Bulger's racketeering trial.

The 83-year-old Bulger is charged with participating in 19 killings during the 1970s and '80s while allegedly leading the Winter Hill Gang. He was one of the nation's most wanted fugitives after fleeing Boston in 1994, and was finally captured in Santa Monica, Calif., in 2011.

King testified that around the time of her husband's disappearance, she saw Bulger getting into a car outside Triple O's, a bar in South Boston that was used by Bulger's gang, and asked him if he knew what happened to her husband.

Bulger told her "that he was probably in Canada robbing banks," and "that's what he originally wanted to do," King said.

When asked by Assistant U.S. Attorney Zachary Hafer what Bulger's demeanor was, King said, "I am sure he was a little agitated that I would even bother him ... I was quite upset."

Prosecutors say Bulger hit man John Martorano shot Tommy King because Bulger saw him as a threat. They say the Bulger gang killed Leonard the following day in an attempt to divert attention from King's disappearance.

Leonard's brother, Joseph Leonard, told the jury he received a call in the middle of the night to come to the morgue to identify his brother's body.

"It was my brother, and he had been shot many times ... his teeth were covered with his own blood," he said.

Sandra Castucci, the widow of nightclub owner Richard Castucci, said her husband left the house on Dec. 29, 1976, but did not return. Prosecutors say Castucci was killed by Bulger's gang after former FBI Agent John Connolly told Bulger that Castucci had become an informant and had told the FBI where two members of the gang were hiding in New York.

Sandra Castucci said Bulger's partner, Stephen "The Rifleman" Flemmi, came to her house after her husband was killed and said he would take over her husband's share of the Squire Club to "make sure I got my checks every week."

She said she was later summoned to a meeting in Providence, R.I., with mob boss Raymond Patriarca.

"He said that my husband owed him money and that he was going to take his end of the club," she said.

Castucci became tearful when she was asked to identify a photo of her husband.

"That's my husband with Frank Sinatra," she said. The photo shows Castucci with the singer at the wedding of Sammy Davis Jr., she said.

She said her husband played golf with Davis and met Sinatra that day at Davis' wedding.

Castucci said she did not know before her husband's death that he was a member of the Patriarca group.

Bulger's lawyers have challenged the credibility of three former Bulger associates who have agreed to testify against him, including Martorano, who spent three days on the witness stand. Flemmi and former Bulger lieutenant Kevin Weeks are also expected to testify.

James Marra, a special agent with the Justice Department's Office of the Attorney General, also spent hours on the witness stand testifying for prosecutors Monday and Tuesday by reviewing reports in a 700-page FBI file on Bulger's alleged role as an informant.

Bulger's lawyers deny that Bulger was ever an FBI informant.

Marra said that based on documents in the file, Bulger was an informant from 1975 until 1990, providing information on the rival New England Mafia as well as other criminals in the Boston area.

Under cross-examination by Bulger attorney Hank Brennan on Tuesday, Marra acknowledged that former FBI agents John Connolly and John Morris both failed to include descriptions of their own wrongdoing in the reports they put in Bulger's file.

"They weren't reporting their own criminal activity," Marra said.

Connolly was convicted of crimes accusing him of tipping off Bulger and other gang members to an upcoming indictment, prompting Bulger to flee. Morris, who received immunity, admitted accepting cash from Bulger. Morris is expected to testify Wednesday.