(Charles Dharapak — The Associated Press)

Defense Secretary Leon E. Panetta announced Tuesday that he had named Richard H. Carmona, a former U.S. Surgeon General, to lead the panel after multiple federal investigations documented a pattern of “gross mismanagement” at the Dover mortuary. Carmona apparently did not consider it a full-time assignment; on Thursday, he declared that he would run for Arizona’s open Senate seat.

By Friday morning, Carmona had second thoughts about whether he was the right man to get to the bottom of things at Dover. He notified the Pentagon that he was stepping down.

“Secretary Panetta agrees with that decision, and he will name a replacement very soon,” Pentagon Press Secretary George Little said.

Carmona served as surgeon general in the Republican administration of former President George W. Bush but is running for Senate as a Democrat. He also served as a special forces medic in Vietnam and as a deputy sheriff in Arizona. He is seeking the Senate seat of Republican Jon Kyl, who is retiring.

Panetta had touted Carmona’s leadership of the Dover panel as recently as Thursday afternoon at a press conference. The other members of the panel are Fred Franks, a retired Army general who served in the first Persian Gulf War; Ruth Stonesifer, an advocate for military families; former Rep. Vic Snyder (D-Ark.); Garold Huey, a Texas funeral director and retired Air Force mortuary affairs official; Jacquelyn Taylor, executive director of the New England Institute, which offers funeral service education; and Bruce Parks, a forensic pathologist.