Dallas: When a judge told Patrick Waller he was a free man after being wrongly convicted and imprisoned for more than 15 years, the former inmate raised both arms skyward and then collapsed into his mother's embrace.

His sobs were the only sound in an otherwise silent court room on Thursday.

"It's all right, honey," Patricia Cunningham told her son. "It's over. You're out of here. You're going home."

Waller, behind bars since late 1992 for aggravated robbery and aggravated kidnapping stemming from the abduction of a Dallas couple, was proven innocent by DNA testing late last year and released on Thursday. The court hearing that freed him lasted less than five minutes.

"I feel vindicated," said Waller, 38. "I feel thankful. Most of all, I feel blessed."

His release had been all but certain since last week, when the Dallas County District Attorney's office announced that DNA evidence had cleared Waller and matched the profile of another man.

That suspect identified his accomplice, and both men subsequently confessed in front of a grand jury, prosecutors said. Neither man is in prison, and they won't face criminal charges because the statute of limitations has expired.

Waller becomes the 19th man in Dallas County since 2001 shown by DNA evidence to be innocent of the crime for which he was convicted.

That's more than any county in the nation, according to The Innocence Project in New York, a legal center specialising in wrongful conviction cases.