Patrick Flaherty has spent nearly half his life in prison with an equally long stretch still ahead of him. While the Missouri man did commit the crimes for which he was convicted, he makes the case that he received an unusually long sentence and that he and others like him deserve a second chance.

"When I look at my life, I think, I'm 42 years old. My life is defined by a mistake I made 20 years ago, and it doesn't matter what I do, that's the reality of the situation," he told CBS News' Erin Moriarty.

Flaherty could spend another 20 years there.

"I could do another 20 doing the things I've been doing, you know, the classes, the college degrees, the charity projects and I could spend another 20 years getting in trouble and I would go for parole on the same day," he said.

On July 23, 1999, Flaherty waited until 3 a.m., grabbed a BB gun that he says he bought at Wal-Mart, covered his face and then walked in a convenience store. He said he never had any intentions of hurting anyone but the BB gun he bought looks like the real thing, similar to a 9mm handgun, he said. He got away with $128 and two months later, robbed a second convenience store, walking away with $89.

Flaherty committed two more robberies before he was finally caught. He was charged with four counts of first degree armed robbery and although the only weapon was that BB gun, he was also charged for carrying a dangerous instrument.

Asked how he would describe Flaherty back then, his lawyer Rick Sindel said, "He's a kid."

"He was kind of a young man without a lot of clues."

Flaherty took a plea, hoping for mercy. Instead, the judge gave him 10 years for each of the robberies and then she ordered the sentences to run consecutively.

"Then you hear the word 'consecutive, consecutive, consecutive' … and you start thinking in your mind 'My God, that's 40 years,'" Flaherty said.



He has to serve 85 percent of his sentence before he's eligible for parole when he's 57 years old.

"When they took me back to my cell, they came in and handcuffed me to the bench. And when I asked them, you know, 'What are you doing?' They told me 'Oh we're putting you on mandatory suicide watch because of your sentence," Flaherty said.

Retired St. Louis circuit court judge Evelyn Baker believes Flaherty got that sentence because the robberies occurred in a county where judges are elected and need to take a tough stance on criminals regardless of their age.



"We have way too many youngsters incarcerated throughout this country," Baker said.

Judge Baker knows about the harm of excessive sentencing. In 1997, she sentenced a teenager, Bobby Bostic, to 241 years in prison after he committed two armed robberies around Christmas and one of the victims was grazed by a bullet.

"I started regretting that sentence many years later when the studies started coming out in terms of brain development," Baker said. "We really should not be treating children like adults because they're not. Their brains are still forming."

But there is no legal mechanism to undo that sentence. Bostic remains in prison as does Flaherty who, in the past two decades, has earned an undergraduate college degree and is working on his masters. He creates math books for the blind after becoming certified in braille transcription. He has petitioned the Missouri governor to take a new look at his case but he fears the good he has done cannot outweigh the pain he caused.

"I know in a perfect world I should probably say that the emotional harm I caused my victims is what hurts me the most, but it's the hurt I caused my mom. Without a doubt," he said.

The judge who sentenced Flaherty wouldn't discuss his case, but one of his victims, a store clerk did. She said she doesn't feel much sympathy for Flaherty, because she still remembers the terror of having a gun pointed at her. But had Flaherty shot one of his victims with a real gun and received a life sentence, he'd likely to be out of prison earlier.

An earlier version of this story's headline incorrectly identified Flaherty as a teen when he committed the robberies.