(CNN) -- Calling it "the most extreme case" of harboring a fugitive, prosecutors want the girlfriend of reputed mob boss James "Whitey" Bulger to spend the next decade in prison. Catherine Greig is scheduled to be sentenced Tuesday in U.S. District court in Boston.
After more than 16 years on the run, she and Bulger were captured in Santa Monica, California, last July. In a detailed memo prepared for the judge, prosecutors describe Greig as a "partner" who helped Bulger avoid capture. "She not only hid his identity, but also hid the fact Bulger had filled their apartment with weapons, enabling Bulger to avoid capture by violence if necessary."
Bulger, who is being held without bail, was the head of a South Boston Irish gang before he fled an impending racketeering indictment in 1995. He evaded law enforcement for 16 years before he and Greig were arrested in June 2011 in Santa Monica.
The couple had, for several years, hidden in plain sight in the palm-tree-lined, oceanside city near Los Angeles in a three-story building named Princess Eugenia.
After discovering the alleged mobster's location, FBI agents lured the couple into the garage from their third-floor apartment on the pretext that someone had broken into their storage locker, and the duo were taken into custody. Inside the couple's modest two-bedroom, corner apartment, FBI agents discovered assault rifles, a 12-gauge shotgun, many semi-automatic pistols and revolvers, a silencer, a Derringer pistol, multiple hunting knives and bundles of cash.
Prosecutors say Greig could have walked away at any time but protected Bulger instead, and in so doing deprived victims' family members of reasonable justice. Bulger is accused of 19 murders during his reign of terror in South Boston during the 1970s and '80s.
"The sentence ought to take into account the broader effect of Greig's conduct," wrote prosecutors, who are also seeking a $150,000 fine and three years' supervised release.
Bulger's trial is scheduled for November, but his lawyers are arguing there's not enough time to go through the volumes of discovery material they need to prepare Bulger's defense.