Raleigh, North Carolina (CNN) -- For 14 years, Floyd Brown was confined to a mental hospital in North Carolina, accused of murdering an 80-year-old woman. His chief complaint in his psychiatric assessment report: "I was framed."
His case is one of several that have shaken the foundations of the criminal justice system in North Carolina.
In 1993, Brown, then 29, was arrested in Wadesboro, North Carolina, suspected of killing Katherine Lynch. Acting on a tip that an African-American male knew something about the crime, an agent of the North Carolina State Bureau of Investigation brought Brown in for questioning.
Brown didn't match the description in the tip, and there was no physical evidence linking him to the killing. But after a day of questioning, SBI Agent Mark Isley had something even more compelling: A six-page confession that he said Brown had dictated to him.
His lawyers found it unbelievable.
"Floyd could never in a million years make that confession," said Kelley DeAngelus, one of Brown's attorneys. "He doesn't have that capacity, he doesn't have the communication skills, he doesn't have the knowledge, he could never speak with that much definition or detail."
Isley, who is under investigation by the North Carolina Department of Justice, declined to comment.
In the confession, Brown allegedly stated his address, even though, according to DeAngelus, he didn't know where he lived. The confession also quoted Brown as saying he awoke at 6 a.m., even though he couldn't accurately tell time.
But even more surprising to DeAngelus was the sentence structure and logical narrative of the confession. "When I met Floyd, he couldn't put together a single grammatically correct sentence. Everything was in three-word or two-word phrases; having a conversation with him was very difficult."
The only thing Brown wrote on the confession was his own name, misspelling "Brown."
But the confession was enough evidence to commit Brown to Dorothea Dix mental hospital in Raleigh. There, he entered a legal limbo. He was accused of a serious crime, but for years, he was ruled incompetent to stand trial and therefore unable to have his day in court.
Finally, in 2007, DeAngelus and attorney Mike Klinkosum got Brown another hearing, and a last-ditch attempt at freedom. "This was the hearing where if we didn't win here, we really didn't know what we were going to do," DeAngelus said.
At that proceeding, Mark Hazelrigg, one of Brown's doctors at Dorothea Dix, said that Brown wouldn't have been able to dictate the six-page document. "This statement is not made in a language that is typical or even possible for Mr. Brown to make spontaneously on his own," Hazelrigg testified.
In an affidavit, Hazelrigg, the chief of forensic services at Dorothea Dix, continued: "Mr. Brown has a limited vocabulary. His speech is simple and repetitive. Mr. Brown does not use complete sentences. ... As a whole, the alleged confession is too detailed and organized for even a normally intelligent person."
The judge agreed. He freed Brown and ruled that there was no "convincing evidence" to keep him detained at Dorothea Dix. Klinkosum recalls that he didn't seem to understand that he was finally free.
"We were all hugging and so forth, and I saw Floyd, and he was walking back to the holding cell, and I said, 'Where are you going?' And he said, 'Court's over. I gotta go back in here.' "
Three years after being released, Brown, 46, lives with a full-time caretaker and has a job cleaning a school in rural North Carolina.
"I didn't murder nobody," he said. "I got locked up for a crime I didn't do."