Did Buffey have a right to see the DNA results before he entered his plea, as he will argue to the West Virginia Supreme Court? Prosecutors will argue to the West Virginia Supreme Court that he didn’t — because Buffey voluntarily pleaded guilty knowing the DNA test was underway, he could not fault the state for withholding the results. The question in general is, surprisingly, not one the courts have settled.

If the case had gone to trial, the answer would have been straightforward. In the 1963 case Brady v. Maryland, one of the most influential of its time, the U.S. Supreme Court held that before a trial, prosecutors must turn over information that could help a defendant prove his innocence. “Particularly in the state system, the prosecutor has more resources than the defense,” explains Paul Schechtman, a former Manhattan and federal prosecutor. “On those occasions when you find something that suggests the defendant didn’t do it, if you suppress it, you’ve suppressed justice.”

But the Supreme Court has never ruled on whether prosecutors must turn over evidence that could establish a defendant’s innocence before he or she accepts a plea offer. And in that regard, Buffey’s position is hardly unusual. Today, more than 95 percent of cases end in pleas rather than trials, a rate that has risen significantly since the onset of tougher sentencing and larger criminal dockets in the 1980s. Trials increase the workload for judges and prosecutors, and so a defendant who is convicted at trial often faces what’s known as a “trial penalty” — a far harsher sentence than the plea offer.

As a result, as the Supreme Court said in 2012, plea bargaining “is not some adjunct to the criminal-justice system, it is the criminal-justice system.” About 10 percent of the 1,800 or so exonerations that have taken place since 1989 involve defendants who pleaded guilty, according to the Innocence Project. That’s true for both DNA exonerations and other kinds of cases.

David Romano, the assistant prosecuting attorney, doesn’t think Buffey falsely confessed. “He told three officers he was in that house,” he told me over the phone. False confessions “only happen when someone is of low intelligence or something else has overcome their will.” In fact, while low I.Q. is one contributing factor in false confessions, there are many more, according to the University of Virginia law professor Brandon Garrett, author of “Convicting the Innocent: Where Criminal Prosecutions Go Wrong.” “Many false confessions involve people who are vulnerable because they are mentally ill, or juveniles, but in many other cases people have no limitations like that,” Garrett said. “They’re just worn down by the questioning, and they thought they could clear up the misunderstanding once they get out of the interrogation room.”

It’s exceedingly difficult to walk back a confession, as Buffey discovered. At a 2004 hearing following his petition, prosecutors argued that the DNA results were “inconclusive” as to Buffey’s guilt, because of the trace DNA from the second male. Ronald Perry, one of the two friends arrested with Buffey for the break-ins, testified that Buffey told him he and a cousin had taken turns holding the victim down and raping her. This contradicted the victim’s own statements; she had never mentioned a second perpetrator to the police, and when asked by a nurse who examined her whether there was more than one assailant, she said no. (At the time of his testimony, Perry asked the prosecutor for help getting his sentence reduced based on the assistance he provided in Buffey’s case. The second friend who initially implicated Buffey in the rape later recanted.) Still, the judge ruled against Buffey.

In 2010, the Innocence Project and a West Virginia lawyer, Allan Karlin, began representing Buffey and retested the DNA. The results were “profoundly exculpatory,” as a brief filed on Buffey’s behalf by Schechtman and signed by 30 other former prosecutors puts it. Then in 2012, after an 18-month battle, the organization won a court order to run the DNA from the rape through Codis, the national criminal-justice database. The search produced a match: The source of the DNA was a man named Adam Bowers. At the time of the rape, Bowers was 16 and lived a few blocks from the victim. He’d also been accused or trying to rape another woman in October 2001, and he was in prison for a home-invasion burglary.