IN THE SPRING of 2009, Attorney General Eric H. Holder Jr. took the extraordinary step of asking a federal judge to dismiss corruption charges against former senator Ted Stevens (R-Alaska). This was no easy decision.

Mr. Stevens had been prosecuted by the Justice Department’s vaunted Public Integrity Section and convicted of failing to report hundreds of thousands of dollars’ worth of gifts from an Alaskan oil services firm and its former chief executive. Yet Mr. Holder rightly sought a reversal of the conviction and vowed not to relaunch the prosecution after learning that his lawyers had failed to turn over information to the defense that could have called the government’s case into question.

This month, Judge Emmet G. Sullivan, who presided over the Stevens proceedings, offered additional evidence of the prosecutors’ misconduct. The judge quoted from sections of a 500-page report produced by a special investigator he appointed to review the debacle. Some of the failures, the investigator concluded, were not inadvertent but were “willful and intentional.” Prosecutors’ handling of the case was “permeated by the systematic concealment of significant exculpatory evidence”; the investigation found instances of wrongdoing that were previously unknown.

Judge Sullivan placed the report under seal to allow Justice Department and defense lawyers to review it and offer objections for why it should not be made public. Barring extraordinary developments, the judge has indicated that he could release the full report in January.

What punishment will befall the prosecutors who committed these egregious violations? That’s unclear. The investigator, Henry F. Schuelke III, was asked by the judge to determine whether they should be prosecuted for criminal contempt of court. Mr. Schuelke, a respected defense lawyer and former federal prosecutor, said no. The reason: A lawyer cannot be held in criminal contempt unless he willfully violates a clear and direct order from a judge. In the Stevens case, Judge Sullivan did not issue an order directing the prosecutors to abide by the law.

Is Judge Sullivan to blame? Of course not. Prosecutors are well-acquainted with and frequently chafe at laws that require disclosure of evidence potentially beneficial to a defendant. Judge Sullivan castigated the Stevens prosecutors on several occasions for appearing to flout these strictures.

Criminal contempt charges are not the only means by which wrongdoers may be held accountable. Mr. Holder should ask for an independent assessment of whether the culpable attorneys should be prosecuted for obstruction of justice. The Justice Department’s Office of Professional Responsibility, which polices prosecutors, is conducting its own investigation; Mr. Holder should make its report public, as promised. The Justice Department should refer the report to the state bar associations that licensed these lawyers, so that they may consider disbarment or other punishments. A lawyer who commits acts of bad faith should never be entrusted with the kind of power prosecutors wield.