The immediate reaction to the Supreme Court’s decision in the Osborne case has been both ill-informed and negative. And liberals are already spinning it as the Roberts Court’s latest affront to justice. This is no surprise. It’s easy for political hacks to attack decisions when the public doesn’t understand the facts of the case. Understand the facts in Osborne, however, and it becomes clear that the decision was plain common sense.

The Court held that individuals who have been convicted of crimes have no constitutional right to access evidence held by the state for DNA testing. The key to the decision is that several of those words have very specific meanings:

Convicted of Crimes: The ruling applies to criminals who have already been found guilty in a court of law, not to individuals merely accused of a crime, who do have a right to access and test such evidence. Once a person goes from being a suspect to a convicted criminal, the court explained, he does not have a constitutional right to retest evidence with every new technology that becomes available in the hope that one of them will cast doubt on his conviction by a jury.

Constitutional Right: In many cases, a convict will have a right to test evidence. But this isn’t a constitutional right. As the Court explained, most states, as well as the federal government, do allow such testing under certain circumstances, such as claims of actual innocence. Convicts may have a procedural right to such testing when such a law applies—that is, the law must be carried out fairly. But to do this, convicts must go through normal post-conviction proceedings and cannot attempt, as here, to short-circuit the law.

DNA Testing: Testing cuts both ways: it can show innocence or it can show guilt. For that reason, criminal defendants who are actually guilty resist giving DNA evidence or using it as a part of their case. That’s what happened here: The convict’s lawyer, believing him to be guilty, rejected using a more accurate DNA test for fear it would prevent a “mistaken identity” defense. Had the Court come out the other way, it would give criminals two bites at the apple: ignore DNA evidence at trial and, if that doesn’t work, claim a right to essentially retry the case after conviction.

The facts of this case show how these principles come together. Osborne was convicted of kidnapping, assault, and sexual assault based on evidence including semen evidence analyzed under the DQ Alpha testing method, which matched Osborne. The DQ Alpha method can only narrow a sample down to approximately 5 percent of the population.

Osborne’s lawyer chose not to use the more accurate RFLP method of DNA testing available at the time, because she thought that he was guilty and planned a “mistaken identity” defense, which a positive identification by the more accurate method would scuttle. But the jury didn’t buy it, and Osborne was convicted. Finding it “nearly miraculous” that Osborne’s victim had survived his brutal assault, the judge sentenced Osborne to 26 years. Osborne appealed and lost.

After 14 years in prison, he was released on parole in 2007. Almost immediately, he committed another crime and was rearrested.

When he filed his first challenge to the conviction in Alaska court, the state supreme court determined that a convict had a right to DNA evidence when the conviction was based on eyewitness identification, there was doubt concerning the perpetrator’s identity, and scientific evidence would give a conclusive result. Osborne fell far short of that standard: he gave a sworn confession to the crime and boatloads of other evidence tied him to it, including the DNA test that had been performed.

So this case is not a case about doing justice. It’s really about the latest attempt to give convicted criminals yet another bite at the apple, in addition to the several they already have, and another opportunity to bog down the justice system with more frivolous appeals over evidence that’s already been played out. Understanding that, the Court got it right.