COLUMBIA, Missouri (CNN) -- Ryan Ferguson was just a teenager when he was arrested in Missouri in 2004, accused of killing Columbia Tribune sports editor Kent Heitholt three years earlier.
Implicated by a former friend who said he had dream-like memories of committing the crime, Ferguson was convicted in 2005 for Heitholt's murder and given a 40-year sentence.
Last year, the same friend admitted in court that he lied, as did a janitor who originally placed Ferguson at the crime scene. For 10 years, Ferguson has sat in prison for a crime he always said he did not commit.
Tuesday night, he walked free, less than a week after an appeals court overturned his conviction, ruling prosecutors withheld evidence in the trial. His release came hours after Missouri Attorney General Chris Koster announced he would not retry Ferguson.
He found out about the decision when his lawyer appeared at the prison, holding up a piece of paper behind protective glass. On it she had quickly scrawled two words: "It's over."
"I feel like Jay Leno or something," a beaming Ferguson joked to cheering supporters after his release.
Now 29, he faces a new world.
"He has no college education and has never sent a text, posted a Facebook update or used a smartphone," according to the Free Ryan Ferguson website, set up by his family and supporters.
He acknowledged after his release that while in prison, he never allowed himself to "look too far into the future." But he has been reading, studying, taking care of himself and "preparing for my life."
His first stop was for ice cream at a Dairy Queen after leaving the courthouse.