"Whatever your truth is, you have to stick with it," Dupree, 51, said Tuesday, minutes after a Dallas judge overturned his conviction.
Nationally, only two others exonerated by DNA evidence spent more time in prison, according to the Innocence Project, a New York legal center that specializes in wrongful conviction cases and represented Dupree. James Bain was wrongly imprisoned for 35 years in Florida, and Lawrence McKinney spent more than 31 years in a Tennessee prison.
Dupree was sentenced to 75 years in prison in 1980 for the rape and robbery of a 26-year-old Dallas woman a year earlier. He was released in July on mandatory supervision, and lived under house arrest until October. About a week after his release, DNA test results came back proving his innocence in the sexual assault.
A day after his release, Dupree married his fiancee, Selma. The couple met two decades ago while he was in prison.
His exoneration hearing was delayed until Tuesday while authorities retested the DNA and made sure it was a match to the victim. Dallas County District Attorney Craig Watkins supported Dupree's innocence claim.
Looking fit and trim in a dark suit, Dupree stood through most of the short hearing, until state district Judge Don Adams told him, "You're free to go." One of Dupree's lawyers, Innocence Project Co-Director Barry Scheck, called it "a glorious day."
"It's a joy to be free again," Dupree said.
This latest wait was nothing for Dupree, who was up for parole as recently as 2004. He was set to be released and thought he was going home, until he learned he first would have to attend a sex offender treatment program.
Those in the program had to go through what is known as the "four R's." They are recognition, remorse, restitution and resolution, said Jim Shoemaker, who served two years with Dupree in the Boyd Unit south of Dallas.
"He couldn't get past the first part," said Shoemaker, who drove up from Houston to attend Dupree's hearing.
Shoemaker said he spent years talking to Dupree in the prison recreation yard, and always believed his innocence.
"I got a lot of flak from the guys on the block," Shoemaker said. "But I always believed him. He has a quiet, peaceful demeanor."
Under Texas compensation laws for the wrongly imprisoned, Dupree is eligible for $80,000 for each year he was behind bars, plus a lifetime annuity. He could receive $2.4 million in a lump sum that is not subject to federal income tax.
The compensation law, the nation's most generous, was passed in 2009 by the Texas Legislature after dozens of wrongly convicted men were released from prison. Texas has freed 41 wrongly convicted inmates through DNA since 2001 -- more than any other state.
Dallas County's record of DNA exonerations -- Dupree is No. 21 -- is unmatched nationally because the county crime lab maintains biological evidence even decades after a conviction, leaving samples available to test. In addition, Watkins, the DA, has cooperated with innocence groups in reviewing hundreds of requests by inmates for DNA testing.
Watkins, the first black district attorney in Texas history, has also pointed to what he calls "a convict-at-all-costs mentality" that he says permeated his office before he arrived in 2007.
At least a dozen other exonerated former inmates from the Dallas area who collectively served more than 100 years in prison upheld a local tradition by attending the hearing and welcoming the newest member of their unfortunate fraternity. One of them, James Giles, presented Dupree with a $100 bill as a way to get his life restarted.
At one point, Scheck pointed out that eyewitness misidentification -- the most common cause of wrongful convictions -- was the key factor that sent Dupree to prison. The attorney then asked how many of the others were wrongly imprisoned because an eyewitness mistakenly identified them. A dozen hands went in the air.
Not in attendance Tuesday was Dupree's accused accomplice, Anthony Massingill, who was convicted in the same case and sentenced to life in prison on another sexual assault. The same DNA testing that cleared Dupree also cleared Massingill. He says he is innocent, but remains behind bars while authorities test DNA in the second case.
Dupree was 20 when he was arrested in December 1979 while walking to a party with Massingill. Authorities said they matched the description of a different rape and robbery that had occurred the previous day.
Police presented their pictures in a photo array to the victim. She picked out Massingill and Dupree. Her male companion, who also was robbed, did not pick out either man when showed the same photo lineup.
Dupree was convicted of aggravated robbery with a deadly weapon. According to court documents, the woman and her male companion stopped at a Dallas liquor store in November 1979 to buy cigarettes and use a payphone. As they returned to their car, two men, at least one of whom was armed, forced their way into the vehicle and ordered them to drive. They also demanded money from the two victims.
The men eventually ordered the car to the side of the road and forced the male driver out of the car. The woman attempted to flee but was pulled back inside.
The perpetrators drove the woman to a nearby park, where they raped her at gunpoint. They debated killing her but eventually let her live, keeping her rabbit-fur coat and her driver's license and warning her they would kill her if she reported the assault to police. The victim ran to the nearest highway and collapsed unconscious by the side of the road, where she was discovered.
Dupree was convicted and spent the next three decades appealing. The Court of Criminal Appeals turned him down three times.