Attorney General Michael B. Mukasey said Wednesday that the Justice Department had elevated its inquiry into the destruction of Central Intelligence Agency interrogation videotapes to a formal criminal investigation headed by a career federal prosecutor.
The announcement is the first indication that investigators have concluded on a preliminary basis that C.I.A. officers, possibly along with other government officials, may have committed criminal acts in their handling of the tapes, which recorded the interrogations in 2002 of two operatives with Al Qaeda and were destroyed in 2005.
C.I.A. officials have for years feared becoming entangled in a criminal investigation involving alleged improprieties in secret counterterrorism programs. Now, the investigation and a probable grand jury inquiry will scrutinize the actions of some of the highest-ranking current and former officials at the agency.
The tapes were never provided to the courts or to the Sept. 11 commission, which had requested all C.I.A. documents related to Qaeda prisoners. The question of whether to destroy the tapes was for nearly three years the subject of deliberations among lawyers at the highest levels of the Bush administration.
Justice Department officials declined to specify what crimes might be under investigation, but government lawyers have said the inquiry will probably focus on whether the destruction of the tapes involved criminal obstruction of justice and related false-statement offenses.
Mr. Mukasey assigned John H. Durham, a veteran federal prosecutor from Connecticut, to lead the criminal inquiry in tandem with the Federal Bureau of Investigation. The appointment of a prosecutor from outside Washington was an unusual move, and it suggested that Mr. Mukasey wanted to give the investigation the appearance of an extra measure of independence, after complaints from lawmakers in both parties that Mr. Mukasey’s predecessor, Alberto R. Gonzales, had allowed politics to influence the Justice Department’s judgment.
Mr. Durham was not appointed as a special counsel in this case, a step sought by some Congressional Democrats. He will have less expansive authority than a special counsel and will report to the deputy attorney general rather than assume the powers of the attorney general, which he would have had as a special counsel.
Mr. Durham has spent years bringing cases against organized crime figures in Hartford and Boston. In legal circles he has the reputation of a tough, tight-lipped litigator who compiled a stellar track record against the mob.