RALEIGH, N.C. — More than a year after shocking allegations emerged about Duke University’s lacrosse team, prosecutor Mike Nifong was back in court yesterday — this time as the defendant.

The North Carolina State Bar charged the Durham County district attorney with several violations of the state’s rules of professional conduct, all tied to his handling of the lacrosse case.

If convicted by a disciplinary commission hearing the case, he could be stripped of his license to practice law in the state.

Mr. Nifong won indictments against three lacrosse players last year after a woman hired as a stripper for a team party in March 2006 said she was raped. One of three had graduated, but Duke suspended the other two. Criticism of Mr. Nifong’s evidence and handling of the case increased through the summer, then when the bar filed its initial ethics charges, Mr. Nifong turned the case over to the state attorney general, who dropped all the charges.

“This didn’t have to happen, and the horrible consequences were entirely foreseeable,” Katherine Jean, the bar official prosecuting Mr. Nifong, said during her 25-minute opening statement. “The harm done to these three young men and their families and the justice system of North Carolina is devastating.”

The trial is expected to run for five days, and the hearing commission chairman promised a quick verdict. Reporters and observers packed the state Court of Appeals courtroom where the hearing was being held. Mr. Finnerty and the third player, Reade Seligmann, are expected to attend the trial at some point. Attorneys for all three players were in the courtroom yesterday.