In 1976, Porter robbed a Winston-Salem convenience store and raped a female clerk.
He says he understands the public's outrage.
"I didn't have any business doing that, I didn't have any business at all," Porter said. "I was wrong, I was shame. If I was out had my own daughter, my own kids and somebody did that, I would feel the same way they feel."
The court has upheld a 1970's law that defined life in prison as 80 years. The state's Fair Sentencing Act in 1981 reduced those sentences by half.
But with or without that state Supreme Court ruling, Porter was bound to be a free man with good behavior under an early release program. He was set to be released in June 2010.
The Vietnam veteran who claims drugs and booze pushed him over the edge, says he would never rape again.
Porter says he is convinced his newfound faith and sex offender rehabilitation classes have saved him. Years ago, he wrote a letter to the woman he raped.
"I hope she received it and I hope that she forgives me and everything, maybe she can't ever do it," he said.
Authorities have not been able to find the woman Porter attacked 33 years ago.
"Still can't find this one and we don't know if we'll ever find her," Forsyth County DA Thomas Keith said.
Keith's staff is also looking for victims in two other inmate release cases.
"The court system said we will take care of you for his natural life and guess where he is now," Keith said.
The past is no easy thing to erase, but the future Porter says is anybody's guess.
"I know one thing, I was wrong for what happened that night and I feel inside of myself that that ain't going to never happen no more …but you never know what's going to happen in life, there's no guarantees," Porter said.