When Mr. McCollum was finally released, his father and stepmother, James and Priscilla McCollum, began to cry and shout for joy as the son they call Buddy stepped out in a houndstooth jacket, khaki pants and slate blue tie he had been given by the lawyers who helped secure his release. The legal team, from the Center for Death Penalty Litigation, began weeping and hugging as well. Standing a free man in fresh air for the first time in his adult life, Mr. McCollum swatted away gnats as he faced a phalanx of television cameras. He told the reporters that his faith in God had sustained him through years of fear that the legal system that had wrongly incarcerated him would also wrongly take his life.

Mr. McCollum also spoke of the 152 men still on death row in the state prison, whom he called his family. “You’ve still got innocent people on North Carolina death row,” he said. “Also you’ve got some guys who should not have gotten the death penalty. That’s wrong. You got to do something about those guys.”

Finally free, Mr. McCollum, who like Mr. Brown is mentally disabled — Mr. Brown’s I.Q. in tests has registered as low as 51 — faces the challenge of his life: learning to live in a world he has not experienced since he was a teenager three decades ago. On death row, Mr. McCollum was never allowed to open a door, turn on the light switch or use a zipper. He never had a cellphone and until last week had not used the Internet. (He excitedly told his stepmother about his first use of Google Maps days ago, when he saw pictures of her house.)

When he got into the family car, a navy Dodge Journey, he sheepishly slipped the beige shoulder belt around his neck and let it hang, unsure of how to use it.