PORTLAND (AP) – A longtime violent criminal, Robert Payzant was regarded as a model prisoner during his 23 years behind bars. But once on the outside, it wasn’t long before he was in trouble again.

Payzant started using cocaine on his first night of freedom in January 2005. Ten months later, he had viciously beaten a stranger in an L.L. Bean employee parking lot to steal money for drugs.

Payzant, 39, of Freeport, was sentenced Wednesday in Cumberland County Superior Court to 18 years for robbery, aggravated assault and other charges. He faces six years of probation after his release.

While in prison, the tall and burly Payzant was regarded as a positive leader who ran a counseling program for fellow inmates to prepare them for life after their release.

“I learned a lot of things, but I learned every one of them in prison,” he told Justice Thomas Warren during Wednesday’s sentencing hearing. “I never learned anything out here.”

In deciding on a sentence, the judge said he had to balance Payzant’s criminal history with the chance that he might someday rehabilitate himself.

“I don’t think that there’s any argument that the system doesn’t adequately prepare people for re-entering society,” Warren said. “This case is a glaring example of that.”

Payzant apologized to David Crosby, who suffered a broken jaw and was knocked unconscious during the Oct. 18, 2005 attack. Crosby saw a man looking into car windows and asked if he needed help. The man then punched Crosby in the face. Police arrested Payzant after a high-speed chase in which he wrecked a stolen car.

“What I’m asking you to do is not to put aside what I did to Mr. Crosby,” Payzant said in court. “I’m asking you to look at me and see within me something that is redeemable. I need something to strive for. I need a reason to strive.”

Deputy District Attorney Meg Elam said Payzant, who grew up in Freeport, has one of the worst criminal histories she has seen in her 20 years as a prosecutor.

He was 16 when he was convicted as an adult for burglary. At 17, he pleaded guilty to robbery after brandishing a realistic-looking pellet gun and stealing a car. At 19, he violated probation and was returned to jail. Two years later, a jury found him guilty of two armed robberies of taxicab drivers and a judge sentenced him to 20 years in prison.

“Mr. Payzant is the kind of person from whom we have to be protected,” Elam said. “I just don’t think there is any evidence that Mr. Payzant can behave any differently than he behaved here.”

But others said they detected a capacity for change.

John Gillis, a member of Kairos, a Christian ministry that holds regular retreats inside prisons, said he was impressed at how Payzant worked with the prison education department to put together a prerelease education program for other inmates.

Gillis said he now realizes that Payzant, having spent most of his life behind bars, lacked the support he needed to survive outside the structure of prison.

“People ask if Mr. Payzant deserves a second chance. Mr. Payzant has never had a first chance,” Gillis said.