When 61-year-old Jeff Mizanskey tells other inmates he’s serving time in prison for a marijuana charge, he says they don’t believe him. They don’t believe him, he says, because he’s serving a life sentence.

“I’m pretty much a loner out here,” he told KCTV5, which reported that after more than 20 years behind bars in the Missouri Department of Corrections, he’s serving the harshest punishment possible for marijuana.

Mizanskey’s case has come in and out public view as he appealed his conviction in 1995, in 1997 and again in 2011. His son created a petition requesting clemency that drew some 370,000 signatures and delivered it in April along with other supporters to the governor of Missouri in Jefferson City, the River Front Times reported. Now, Mizanskey’s asking citizens to send letters to the governor on his behalf, the news site reported.

At a time when two states have legalized the sale and consumption of recreational marijuana and 23 have legalized it for medical use, some — including Mizanskey’s prosecutor — said the term may be too harsh.

“Think about it, it’s the harshest, most severe penalty that anyone has ever received for a drug crime in Pettis County,” Jeff Mittelhauser, the former prosecutor who helped put Mizanskey away, told KCTV5. “I would support his request for clemency, if he would stop misinterpreting his criminal history, and his involvement in the offense.”

Mittelhauser was likely referring to Mizanskey’s claim that he wasn’t intentionally involved in the last deal that put him behind bars.

It was 1993. Christmas was just a week away and Mizanskey found himself in the middle of another marijuana bust. Mizanskey claimed he was giving a ride to a friend who had arranged to purchase pot from an informant in a hotel room. He claimed he wasn’t involved — but he was there. And with two other weed-related incidents on record, it didn’t look good for him.

Mizanskey had been busted for selling an ounce and possessing more than 35 grams in 1984, and again for possessing more than 35 grams in 1991, according to his clemency plea. This time, he was arrested and charged with possession with intent to deliver and distribute, court records show.

Under Missouri’s “prior and persistent drug offender” statute, similar to the “three strike” rule in a few other states, he was sentenced to life in prison without possibility of parole. None of his pot-related crimes allegedly involved weapons, violence, juveniles or other aggravating factors, according to his clemency plea.

Still, this was felony No. 3.

Two decades later, Mizanskey is still behind bars. He has reportedly exhausted his appeals and can only be released if Gov. Jay Nixon (D) grants his request for clemency, according to news reports.

In April, a River Front Times reporter asked Nixon if he thought it was “just” for a person to serve a life term without parole for a nonviolent offense.

“I think each case is separate, and we look at the entirety of their record and their cases, and we have a process in place to review all that,” Nixon said. “So I don’t just pick a single act or occurrence out. We look at what the complete history is and we’ll give all of these a full and thorough review.”

Nixon’s press secretary Scott Holste told KMOX in April that the governor’s office had received the clemency request and was reviewing it.

With Mizanskey still prison, his son Chris told KMOX that it’s time for the governor to free his father.

“I plead with him to let my dad out of prison because he’s been there 20 years and missed a whole lifetime of stuff,” he said. “My nieces, his grand kids, my nephews, all those people that haven’t had time to spend with him like I did when I was younger. The man was a perfect dad, a perfect friend, and he was always out to help people.”