The statute allowing Wyoming courts to retry cases if DNA evidence was presented was approved in 2008 with the assistance of state prosecutors and attorneys from the Utah-based Rocky Mountain Innocence Center, who have been working on Johnson's case for more than a decade.
"We're very thrilled," said Innocence Center attorney Elizabeth Fasse. "It's been a really long road to get to this point."
Although Johnson was granted a new trial, he remains behind bars.
On Tuesday, his bail was reduced to $10,000, but Fasse said it did little to quell the dissatisfaction of Johnson's family.
"The reaction was a bit muted," Fasse said. "Andrew has maintained his innocence from the time of his arrest throughout his incarceration and trial. He's been fighting for so many years on his own to prove his innocence. I think it's just frustrating."
According to a Wyoming Supreme Court decision, Johnson on June 10, 1989, was drinking at a Cheyenne bar with friends and the victim, whom he knew through the victim's fiancé.
Johnson and the victim continued to go from bar to bar before the woman left Johnson at a bar parking lot.
The woman went home, and later in the evening, a man whom the victim identified as Johnson broke into her home and raped her.
Johnson had petitioned the Supreme Court for a new hearing in 1991 based on issues at trial, but that was denied.
Attorneys with the Innocence Center said they believe the DNA evidence will be enough to exonerate Johnson, though prosecutors have said they have other evidence in the case.
The recent DNA tests show Johnson was not the source of the male DNA taken from the victim after the 1989 attack. The DNA instead matched the victim's fiancé at the time.