While there is some merit in making it hard to overturn a criminal verdict, given the incentive of every single person convicted to do so (and indeed, the courts and professional disciplinary bodies are awash with prisoners petitions in every conceivable forum that are dismissed summarily 99.9% of the time), it is also the case that the innocent are systemmically the most likely to take cases to trial even when their defenses are objectively hard to prove, and what evidence we have of the accuracy of the jury trial system suggests that wrongful convictions aren't terribly unusual.
Alan Prendergast in his feature story in Westword, "Sexual abuse lies keep man in prison; courts refuse to hold new trial" (July 20, 2011) made that point particularly powerfully in the case of Charles Farrar, whose stepdaughter accuser recanted her testimony of sexual abuse shortly after his conviction in 2002 (preventing a trial of her mother on related charges), that left him with a 145 years to life sentence that prosecutors and the courts have refused to revisit so far.
An update to the story on August 2, 2011 notes:
Days after our cover story on the Farrar case attracted widespread attention, Arapahoe District Judge Valeria Spencer ruled on Farrar's motion for reconsideration of his sentence, which was filed in her court nearly two years ago. Spencer denied the request, stating that Sacha's 2003 recantation failed to meet the standard of "exceptional, unusual, and extenuating circumstances" that would warrant a reduction in the hundred-plus years Farrar is required to serve for his conviction on 22 counts of sexual abuse.
Farrar had previously sought to have his conviction overturned, based on the "new evidence" of the recantation. His attorneys argued that, since the prosecution's case consisted largely of Sacha's testimony -- there was no evidence to support her account of having endured years of sexual abuse by Farrar and her own mother, and little indication that investigators had even bothered to interview other potential witnesses -- her claims were invalidated when she later admitted to committing perjury and concocting the allegations in order to go live with her grandparents.
The trial judge, John Leopold, denied that motion shortly before his retirement; in 2009 the Colorado Supreme Court upheld Leopold's ruling 4-3. Farrar's attorneys then sought to have his sentence trimmed, based on the recantation and his exemplary prison record. But Judge Spencer followed Leopold's reasoning that state law requires courts to regard all recantations of sexual abuse claims with suspicion because of the presumed pressure on victims by other family members to "make things right."
Notably, his case is in the judicial district where Carol Chambers, the nationally notorious "tough on crime" District Attorney with a poor record for following the norms of that profession in the state, presides.
There are potentially two other outs for Farrar.
First, he could bring a collateral attack in a federal habeas corpus petition, but the substantive law there is extremely hostile to claims of actual innocence when there were no violations of constitutional rights that took place on the record in the courtroom itself (although there were indications of prosecutorial misconduct and recantation at the state level collateral attack that arguably were judges under the wrong standard by the Colorado courts). Few cases prevail in non-capital federal habeas petitions, however, since the applicable legal standard is so deferrential to state courts.
Alternately, Governor Hickenlooper (or any subsequent Governor of the State of Colorado) could grant him executive clemency, which is subject to no specific standards and very little formal process that binds the Governor, although the practice has become increasingly rare. This case is arguably an exceptionally appropriate choice to act since it is what the alleged victim herself has sought since very shortly after the conviction, since a detailed exposee has cast doubt on the accuracy of the result and the integrity of the process, since there is a grave injustice given the long sentence involved that will not become moot, and since Farrar's prison conduct has been exemplary.