They also interviewed Donnell's widow, who they say claimed Donnell became violent when he drank. The report also says Donnell's neighbors claimed he wore a windbreaker similar to one found at the crime scene, and was spotted cleaning out his truck a few days after the murders.
The group's biggest find -- and the central point in Skinner's plea to have his case reexamined -- was DNA evidence never tested for trial, partly because Skinner's attorney at the time didn't want it.
Skinner's DNA was found at the crime scene, but Harold Cormer, his attorney at the time, said in reports then that he felt the samples would have implicated Skinner in the killings.
"It was obvious from the start that DNA would determine the truth of what happened in that house," Northwestern's Protess said today in an e-mail to ABC News.
Items not tested included Busby's rape kit, material found under her fingernails, hair and sweat found on the windbreaker, a bloody towel, and knives found at the scene. Protess' group began pressuring the state to test those items, as have Skinner and his current attorney, Robert Owen, for the past 10 years.
Those pleas were finally heard this week. After the Texas Board of Pardons and Paroles declined to recommend a reprieve for Skinner, several state lawmakers began lobbying Texas Governor Rick Perry to grant a reprieve.
Skinner's defenders cite other death-penalty cases in Texas as reasons to reopen this one:
In 2009 several investigative reports said Cameron Todd Willingham, executed in 2004 for killing his three daughters, was wrongfully convicted on the basis of faulty evidence.
Timothy Cole, another man on death row who died of an asthma attack, was given a posthumous pardon by Perry after DNA evidence was finally tested and showed he did not commit the rape of which he was convicted.
"In honor of Tim Cole, I ask that you give Mr. Skinner a 30-day reprieve so that DNA testing can be performed and we can be absolutely certain that Mr. Skinner is truly guilty -- before it's too late," State Sen. Rodney Ellis, D-Houston, wrote to Perry this week.
Perry had not acted as of yesterday, and Skinner was down to his final hour when the Supreme Court issued its stay.
"The application for stay of execution of sentence of death presented to Justice Scalia and by him referred to the Court is granted pending disposition of the petition for a writ of certiorari," the court's order reads in part.
Skinner's stay is indefinite. He has been returned to Death Row for now. But the order does not necessarily mean it will accept Skinner's case for appeal. The court has said it will take more time to review the claims before it decides whether or not to intervene.
At Northwestern, David Protess said he was thrilled when he was told the news Wednesday evening.
"My next reaction was hope -- that the Supreme Court will grant Hank the DNA testing to help determine whether he is truly innocent," he said.
Protess said he is still unsure whether or not Skinner is innocent, but that is part of why this case needs to be reopened.
"That's why we need DNA testing. I wouldn't be pursuing those tests if there weren't substantial holes in the state's case. At this point, I'd say there's reasonable doubt about Hank's guilt," Protess said. "Our ultimate goal is finding truth, whether it's guilt or innocence."