McGonagle was the leader of a gang that competed with Irish gangster boss James "Whitey" Bulgers Winter Hill Gang. Bulger was suspected of involvement in McGonagle's death in 1974 and 18 mob killings 1973 and 1985.
Bulger, the leader of the South Boston Gang, was the ruthless king of a criminal empire who had committed a federal judge as "unfathomable" acts. His notorious reign inspired Jack Nicholson's character in Martin Scorsese's film The Departed. Bulger escaped police for 16 years before being arrested in 2011.
He died Tuesday in a West Virginia prison, an 89-year-old man sentenced to life imprisonment and five years in prison.
Bulger, a longtime FBI informant, was killed at the Hazelton US prison in Bruceton Mills. According to the Federal Penitentiary, he was not approached at 8:20 in the morning.
He was pronounced dead by the medical examiner in Preston County after the rescue operations failed. No other inmates or employees were injured, the prison office said.
The FBI is investigating the death of Bulger, one day after his transfer to the West Virginia facility, the prison office said.
"It's a happy day"
A statement by Andrew Lelling, the US attorney for Massachusetts, was brief on Tuesday. Bulger was not mentioned unless he died.
"We received a message this morning about the death of James" Whitey "Bulger, our thoughts are with his victims and their families," the statement says.
The brother of a woman charged with murder in 1981, CNN said, "It's a happy day."
Steven Davis' 26-year-old sister, Debra Davis, was the girlfriend of Bulger's partner Steve "The Rifleman" Flemmi. Flemmi testified that he had lured Davis into a house where Bulger had strangled her. Flemmi testified that he "unintentionally got Davis out of control," he and Bulger were FBI informants, and Bulger said several times "he wanted to kill Davis" because she knew about the relationship with the FBI.
The defense testified of ex-hitman John Martorano, who confessed that he "accidentally strangled" Davis. Martorano was imprisoned for 12 years, but was released in 2007 to testify against Bulger.
The end of a "16-year honeymoon"
In 1995, Bulger skipped the city from a pending indictment allegedly tipped by a fake FBI agent.
The mob boss, who took Osama bin Laden's place on the FBI's top 10 most wanted list, hid in sight in Santa Monica, California. He and his girlfriend, Catherine Elizabeth Greig, lived blocks under the pseudonym Charlie and Carol Gasko. The wrong name was even on the bell list.
The couple ate a few nights in a white tablecloth operation where Hollywood producers sat and sat in a corner table on the patio behind the restaurant, a manager said. They were generally polite as well. Bulger often wore a hat with a tattered brim, neighbor Catalina Slim told CNN in 2011.
"They were kind of mysterious, even on the phone – you could not call them," she said. "Sometimes I wanted to give them a tip for sale."
A tip led the authorities to him.
In 2011, the FBI lured a presumably unsuspecting Bulger out of his oceanfront home. horn player had He received a phone call and was told that his locker had opened in the parking garage area of the building. The FBI arrested Bulger when he saw it, CNN said.
Bulger would call his years as a refugee with Greig a "16-year honeymoon".
During Bulger's trial, cruel details about the deaths he was charged with turned up.
In the summer of 1983, Bulger organized a meeting with Barrett on the pretext that he had stolen diamonds that he wanted to get rid of. When Barrett appeared in the house, Weeks, Bulger, and Flemmi waited.
You chain Barrett to a chair. For hours, they grill him about a rival gang and local drug dealing, Weeks said.
Barrett tried to buy his way out and told Bulger about his $ 40,000 supply.
Weeks said Bulger left the house to pick up the money while he and another co-worker watched Barrett. When Bulger returned, he told Barrett to go downstairs. Then Bulger put a gun behind Barrett's head and squeezed the trigger, according to Weeks.
"Nothing has happened," said Weeks.
Bulger realized the gun was safe. He removed security and shot Barrett, Weeks said.
"It's just sad that it took so long"
During his conviction, Bulger had no eye contact with relatives of those killed or with those who killed his accomplices in Winter Hill Gang.
He was a convicted murderer in the 1980s. He would probably die in prison.
Carmen Ortiz, the former US Attorney for Massachusetts, who oversees Bulger's prosecution, said she hopes that Bulger's fame has not focused on his victims. Ortiz says she hopes for his death "is the end of a very sad chapter in Boston's history, in which this man has harmed so many people through his brutal crimes."
"He had it to himself and it's just sad that it took so long," said Steven Davis.
Ray Sanchez, Laura Ly, Kristina Sgueglia and Ann O'Neill of CNN contributed to this report. Michael Martinez and Laura Batchelor also contributed to this report.