Two North Carolina men were exonerated earlier this week due to new DNA evidence after spending 30 years in prison, where one was awaiting the death penalty, highlighting the reality that innocent men can end up on death row.

Back in 1994 conservative Supreme Court Justice Antonin Scalia voted against a petition asking the Supreme Court to review the case of one of those men, Henry McCollum. That man became North Carolina's longest-serving death row inmate after he and his half-brother Leon Brown were convicted of raping and killing an 11-year-old girl.

This news brings to mind Scalia's insistence that the Supreme Court has never ruled the Constitution forbids the execution of a convicted defendant who later convinces a court of his innocence, as Slate points out.

"This Court has never held that the Constitution forbids the execution of a convicted defendant who has had a full and fair trial but is later able to convince a habeas court that he is 'actually' innocent," Scalia wrote in a 2009 dissent of the Court's order for a federal trial court in Georgia to consider the case of death row inmate Troy Davis. "Quite to the contrary, we have repeatedly left that question unresolved, while expressing considerable doubt that any claim based on alleged 'actual innocence' is constitutionally cognizable."

The legal definition of "actual innocence" is the absence of facts required to convict someone based on a criminal statute, according to the Legal Information Institute. Defendants appealing convictions seek to prove actual innocence by submitting new evidence that reverses the court's confidence in a past verdict.

The opinion is technically right, Dahlia Lithwick points out in Newsweek. "As a constitutional matter, Scalia's assertion is not wrong," she wrote. "The court has never found a constitutional right for the actually innocent to be free from execution."

Henry McCollum is followed by reporters as he leaves court following his release from Central Prison in Raleigh, North Carolina, Wednesday, Sept. 3, 2014. AP However, Vincent Rossmeier noted in Salon,"His opinion suggested a certain callousness on the question of whether the courts should care if the state puts an innocent man to death, but he was right when he said the Supreme Court has never ruled whether an individual’s 'actual innocence' necessitates the involvement of a federal court in a state conviction."

Chief Justice William H. Rehnquist wrote a 1993 decision that was in line with Scalia's comment that the Supreme Court has never made such a ruling.

But Rehnquist added that the execution of a defendant who has made a particularly strong demonstration of innocence could conceivably be considered unconstitutional. "We may assume ... that in a capital case a truly persuasive demonstration of 'actual innocence' made after trial would render the execution of a defendant unconstitutional and warrant federal habeas relief if there were no state avenue open to process such a claim," Rehnquist wrote in that decision.

Scalia has accepted the fact that the justice system is not perfect, and innocent people will be convicted. “Like other human institutions, courts and juries are not perfect,” he wrote in a 2006 opinion. “One cannot have a system of criminal punishment without accepting the possibility that someone will be punished mistakenly.”