EARLIER THIS SUMMER, a Mississippi jury convicted Edgar Ray Killen of three counts of manslaughter in connection with one of the most infamous crimes of the civil rights era: the 1964 killings of three civil rights workers. Judge Marcus Gordon sentenced the unrepentant 80-year-old to three consecutive 20-year terms in prison -- effectively a life sentence for a man who had escaped justice for four decades. Last week, however, Judge Gordon granted Mr. Killen bail pending his appeal. So on Friday, Mr. Killen -- a preacher who helped organize the group of Klansmen that ambushed, shot and buried James Chaney, Michael Schwerner and Andrew Goodman -- was set free.

Judge Gordon justified the release on the grounds that granting such an appeals bond is generally required by law in manslaughter cases in which the convict is not a danger. But Mississippi law is not as flip as all that. The judge has discretion, and in any event, the burden is on the convict to show "by clear and convincing evidence that [he] would not constitute a special danger to any other person or to the community." And as prosecutors argued Monday in an emergency petition to the state Supreme Court, Mr. Killen simply cannot show this. This is somebody, after all, who orchestrated the deaths of three people. In 1975 he was convicted of felony telephone harassment for threatening to kill someone. On the date of his much-belated arraignment in the civil rights killings, a bomb threat caused the evacuation of the courthouse, and the state attorney general alleges that a relative of Mr. Killen's threatened to kill the trial judge. After his conviction, Mr. Killen made threatening comments to one of his jailers. This simply isn't a man who ought to be on the streets while he challenges his conviction.

The prosecution of Mr. Killen was late and incomplete, resulting as it did in manslaughter, not murder, convictions. But along with other post hoc civil rights prosecutions, it nonetheless stands for a tremendously important proposition: that there is no redemption or amnesty for the crimes of those domestic terrorists who took up arms to fight integration and maintain state-backed white supremacy. First overt, and then latent, sympathy with Mr. Killen allowed him to live openly for 40 years, with his role in the crime a kind of open secret. Federal authorities tried him once for civil rights violations, but a hung jury resulted when a single member refused to convict a preacher. His conviction marked an important rebuke to such tolerance.

Like any convicted criminal, Edgar Ray Killen has a right to appeal, and if his trial had legal defects, his conviction will fall. But until he prevails on appeal, he deserves not a single additional day of freedom.