The hero of the hour has to be Kurt Engelhardt, the federal judge who ruled in 2013 that five cops convicted in the Danziger Bridge bloodbath were entitled to a new trial.

That was pretty brave decision, given universal revulsion over the cowboy officers who opened fired on unarmed civilians in the hectic aftermath of Katrina and then conspired in a cover-up. Engelhardt arrived at his decision only after much agonizing, having initially dismissed the idea that a new trial was warranted, for this is not a wishy-washy judge fixated on the rights of the accused. He was appointed by President George W. Bush and numbers among his closest friends U.S. Sen. and Louisiana gubernatorial candidate David Vitter, so his conservative credentials are beyond challenge.

Same goes in spades for the appeals court, which has just upheld Engelhardt in an opinion written by Edith Jones, generally regarded as its most illiberal member. You couldn’t find a more right-wing judge in the entire country. Engelhardt hardly could have been more spectacularly vindicated.

The ruling represents no vindication for the defendants, however, for they are not getting a retrial because Engelhardt found reason to doubt they committed the crimes of which they were found guilty. Next time around, they will once again be confronted with overwhelming evidence that two innocent people were killed and four wounded in a hail of their reckless gunfire. Police then dropped a gun at the scene and fabricated witness statements in an attempt to blame the victims.

It will, no doubt, be tough for the victims’ families to hear all the grisly details rehashed at a retrial of which they evidently fail to see the point. But the principle of a fair trial must remain sacrosanct, and Engelhardt has done the federal justice system a vital service by clinging to it.

He alone takes the credit, for prosecutors lied and obstructed his efforts at every turn to establish the full extent of their illicit antics. Nevertheless, after two years of painstaking investigation, Engelhardt decided he had no choice but to throw out the convictions on grounds of “grotesque prosecutorial misconduct.”

Grotesque it pretty much had to be for the verdicts to be overturned. The courts are seldom much concerned with misconduct, if it doesn’t change the outcome of a trial. “Harmless error,” they call it. But if the misconduct is so “egregious” that it might “infect the integrity of the proceeding,” the U.S. Supreme Court has ruled, it is not necessary for judges to consider whether the verdict otherwise would have been different.

This proceeding was infected from the moment federal prosecutor Sal Perricone, using various noms de plume, started attaching inflammatory comments to online news stories about Danziger. Then, it turned out that his supervisor, Jan Mann, had been up to the same tricks, after assuring Engelhardt she had no idea what Perricone had been up to. Thus ended the government careers of Perricone, Mann and their boss, U.S. Attorney Jim Letten.

The defense already was pressing for a retrial, and not just over the online effusions. Engelhardt himself had expressed unease over the light sentences granted to errant cops whose testimony helped the feds win long stretches for defendants opting to go on trial. The defense also complained that the feds had coerced one guilty plea and scared three defense witnesses out of testifying with threats of prosecution.

Englehardt, however, was still ferreting out the truth and asked the Department of Justice in Washington to conduct an investigation, which was entrusted to a couple of prosecutors from Georgia. The resultant report was so inconclusive and evasive that it reminded the appeals court of a “whirlpool cycling toward and gradually reaching its drainage outlet.”

The investigators were so slippery that Engelhardt had to corner them in his chambers in order to learn the identity of a Justice Department “employee” who had been posting pro-prosecuting comments about Danziger online, too. It was Karla Dobinsky, a Civil Rights Division attorney, whose role in the case was to ensure that the rights of the indicted officers were protected. It must have been about then that Engelhardt determined the convictions could not stand.

When the feds filed their appeal, they asked for a different judge if a retrial were granted. Prosecutors, after their performance in this case, have quite a nerve to find fault with anyone, and the appeals court duly ruled that Engelhardt is jake.

James Gill can be reached at jgill@theadvocate.com