The Dallas County District Attorney's Office said Monday it supports Dupree's innocence claim.
Dupree has spent more time wrongly imprisoned than any other DNA exoneree in Texas, which has freed 41 wrongly convicted inmates through DNA since 2001, more than any other state. His 30 years would surpass James Woodard, who spent more than 27 years imprisoned for a murder that he was cleared of in 2008.
About two dozen DNA exonerations have happened in Dallas since 2001, more than any other county in the nation. Only two states -- Illinois and New York -- have freed more of the wrongly convicted through DNA evidence, according to the Innocence Project, a New York-based legal center representing Dupree that specializes in wrongful conviction cases.
Dallas' record of DNA exonerations is unmatched nationally because the county crime lab maintains biological evidence even decades after a conviction, leaving samples available to test. In addition, District Attorney Craig Watkins has cooperated with innocence groups in reviewing hundreds of requests by inmates for DNA testing. Watkins, the first black DA in Texas history, has also pointed to what he calls "a convict-at-all-costs mentality" that he says permeated the DA's office before he arrived in 2007.
The DNA testing also excluded a second defendant, Anthony Massingill, who was subsequently convicted in another sexual assault case and sentenced to life in prison. Massingill remains in prison but maintains his innocence. DNA testing in that second case is ongoing.
Dupree was charged in 1979 with raping and robbing a 26-year-old woman and sentenced in 1980 to 75 years in prison for aggravated robbery. He was never tried on the rape charge.
According to court documents, a 26-year-old 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.
About five days later, two men whose descriptions did not match Dupree tried to sell the rabbit-fur coat at a grocery store two miles from the liquor store, according to court documents. The car stolen from the victims was found abandoned in the parking lot.
Dupree and Massingill were arrested in December because they looked similar to two suspects being sought in another sexual assault and robbery. The 26-year-old woman picked both men out of a photo array, but her male companion did not identify either defendant in the same photo array.
Dupree was convicted and spent the next three decades appealing. The Court of Criminal Appeals turned him down three times.
The Innocence Project, which took on his case in 2006, obtained DNA testing last summer on biological evidence taken from a vaginal swab. In July, shortly after Dupree's release, the test results cleared Dupree and Massingill.
The hearing is happening now because authorities needed to confirm that the 30-year-old biological material was a DNA match to the victim.