By Ameet Sachdev and Ray Gibson | In an extraordinary maneuver, the federal appeals court in Chicago removed a judge from an ongoing criminal trial after ruling that he had made an error in the case.

The 7th Circuit U.S. Court of Appeals did not give an explanation in its Tuesday order, which dismissed U.S. District Judge James Holderman from the jury trial of a man facing drug charges. The court said it would follow up with an opinion.

The lack of explanation left court watchers wondering what Holderman did to incite such a harsh penalty. The appellate court reverse judges all the time. But removing one in the middle of a trial may be unprecedented.

His removal “is extraordinary. It really is,” said a criminal defense attorney who asked not to be named. “This is as strong a rebuke an appellate court can give to a sitting court judge.”

The court’s spokesman did not immediately return requests for comment.

During the trial that began July 6, Judge Holderman had refused to allow federal prosecutors to admit fingerprint evidence and testimony against the defendant, Clacy Watson Herrera. The government has accused Herrera of leading an organization that smuggled cocaine and heroin into the United States from Jamaica and Panama. Herrera denies that he had any involvement in the drug smuggling ring.

In an unusual step, prosecutors challenged Holderman’s evidentiary ruling by filing an appeal with the 7th Circuit, which postponed the trial. Holderman responded in court papers that he had not made a final decision on the evidence. On July 22, the judge definitively excluded the evidence, leading to another trial stoppage.

U.S. Atty. Patrick Fitzgerald again asked the appellate court to review the judge’s ruling. But Fitzgerald did not seek Holderman’s removal in his petition.

The U.S. attorney’s office declined to comment. Herrera’s lawyer also declined comment.