Asked if Bogden "fell through the cracks," the Justice official said Bogden's case "could have been handled better," according to an account given by the senior staffer who reviewed the interview.

McNulty was questioned on Friday by staff members representing Republicans and Democrats on the committees.

William Moschella, an assistant attorney general, also was interviewed last week.

They were the fifth and sixth Justice officials, including Gonzales, interviewed in public hearings or behind closed doors in an ongoing investigation into the firing of eight U.S. attorneys last year.

Seven, including Bogden, received telephone calls from Washington on the same day telling them that they were expected to resign.

McNulty expressed hesitation about letting Bogden go in a Dec. 5 e-mail that has already been made public. In it, McNulty said he was "skittish" about firing the Nevadan, who had worked as a federal prosecutor for 17 years, including six as head of the Nevada district.

The official confirmed to investigators that subsequently he backed off when he was told that Bogden was unmarried and did not have children.

He said at that point he deferred to the list. He said it contained names of officials that he could understand why they were being fired, while others were more subjective and not specific.

McNulty told the congressional staffers his failure to speak up more forcefully for Bogden still weighs on him.

Contacted on Tuesday at his home in Reno, Bogden said the account of McNulty's interview is "somewhat consistent" with what the deputy attorney general told him in conversations after he was fired.

"One of my inquiries was whether this had anything to do with the performance of my office and he told me that did not enter into the equation," Bogden said. "But I still don't know who made the decision, who put me on the list, and why?"

Gonzales testified before the Senate Judiciary Committee last month saying that he also did not know why Bogden was being fired.

Although he said he felt badly that Bogden was not told personally why he was being let go, Gonzales said the Nevadan's dismissal will not be reconsidered.

Investigators walked McNulty through a number of issues associated with the firings of the eight prosecutors.

On Bogden, they appeared to focus on two things.

One was to question an assertion that Bogden was "resistant" to prosecute obscenity, seemingly based on an August 2006 complaint by the head of the department's obscenity task force who wanted Bogden to pursue a specific case in Las Vegas.

Investigators wondered if that could really be a reason. They noted in their questioning that Bogden's name first surfaced in a document back in January 2006 -- months earlier -- as someone who had caught the eye of department leaders forming a dismissal list.

The previously reported handwritten addendum at the end of a Jan. 1 memo about potential firings read: "Quiet/not sure about: Bogden." Officials later said the note was written by Monica Goodling, a Gonzales assistant who played a role in the firings.

Secondly, after Bogden was dismissed, Justice officials said the Nevadan was regarded as lackluster and they wanted to get new energy into the state office.

Noting that it usually takes a year for a U.S. attorney to be appointed and get through Senate confirmation, McNulty was asked whether the Nevada office indeed was "energized" by its leader's dismissal.

Moschella was asked the same question.

Investigators did not feel they received satisfactory answers to either question, according to the senior staff member familiar with the interviews.