BOSTON (AP) — As former Boston crime boss James "Whitey" Bulger was led out of a courtroom to begin serving a life sentence for his murderous reign in the 1970s and '80s, questions remained for the families of some of his victims.

Why did federal prosecutors give such generous plea deals to Bulger's cohorts? And did Bulger ever offer to plead guilty, a step that would have avoided the two-month trial?

Relatives of people who were killed by Bulger or his henchmen vented their anger Wednesday during the first part of Bulger's sentencing hearing, calling him a "terrorist," a "punk" and "Satan." But after Bulger was formally sentenced Thursday, some of them also said they thought federal prosecutors should have been able to convict Bulger without giving lenient deals to his partners in crime.

Sandra Patient, whose uncle, Arthur "Bucky" Barrett, was shot in the head by Bulger, called it "ludicrous" that ex-hit man John Martorano and former Bulger protege Kevin Weeks are walking the streets, despite committing horrendous crimes. Both testified against Bulger and provided key evidence.

Martorano, who admitted killing 20 people, spent 12 years behind bars, while Weeks, who admitted aiding in five murders, served five years.

"I don't think there will ever be justice," Patient said.

Federal prosecutors defended their handling of the case and said they feel gratified that they put Bulger and his partner, Stephen "The Rifleman" Flemmi, behind bars for life. Flemmi also testified against Bulger.

At the time prosecutors made a deal with Martorano, he was facing six or seven years on money-laundering charges. He agreed to cooperate with prosecutors and testify against Bulger, and admitted committing 20 murders.

"By pleading guilty, he doubled his time in prison," Assistant U.S. Attorney Brian Kelly said.

"Twelve years is obviously better than six, but is 12 years sufficient for the crimes this guy committed? No, but this is the system we work in."

Assistant U.S. Attorney Fred Wyshak said the plea deal with Martorano was a turning point in the case. At the time, Bulger was a fugitive.

"It brought Weeks to the table, it brought Flemmi to his knees and it resulted in the conviction of Bulger and Flemmi," Wyshak said.

Bulger's sentencing brought to a close a sordid case that exposed FBI complicity in his crimes and left a trail of devastated families whose loved ones were killed by Bulger or his henchmen.

Bulger, the former boss of the Winter Hill Gang, fled the city in 1994 after being tipped off by a former FBI agent that he was about to be indicted. He was a fugitive for more than 16 years until he was captured in Santa Monica, Calif., in 2011.

His disappearance became a major embarrassment for the FBI when it was learned that corrupt Boston agents had taken bribes from Bulger and protected him for years while he worked as an FBI informant, feeding information on the rival New England Mafia.

A jury convicted Bulger in August in a broad racketeering case. He was found guilty in 11 of the 19 killings he was accused of, along with dozens of other gangland crimes, including shakedowns and money laundering.

At his sentencing, Judge Denise Casper read off the names of the 11. She told Bulger she sometimes wished that she and everyone else at his trial were watching a movie because the horrors described — including shootings, the strangling of two women, the removal of teeth from bodies and burials in a basement — were so awful.

"The scope, the callousness, the depravity of your crimes are almost unfathomable," she said.

Casper sentenced Bulger to two consecutive life sentences plus five years, as prosecutors had requested.

Bulger, who was known for his volcanic temper, snarled obscenities at several once-loyal cohorts during his trial, but he said nothing at all at his sentencing.

Bulger's lawyer, J.W. Carney Jr., said outside court that Bulger — after he was captured in 2011 — offered to plead guilty to all the charges against him if prosecutors would give "some consideration" to his longtime girlfriend, Catherine Greig, who spent 16 years on the run with him. Greig is now serving an eight-year prison sentence for helping Bulger while he was a fugitive.

Kelly confirmed that Bulger did offer to plead guilty but made "unreasonable demands," including the immediate release of Greig from prison.

"She committed serious crimes," Kelly said. "I think a lot of people would think it was a cover-up if we gave him a sweetheart deal. We thought it was best to take him to trial."

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