WASHINGTON, March 12  D. Kyle Sampson has never worked full time as a federal prosecutor. But for much of the Bush administration he played a considerable role in vetting who served in the Justice Department. And last year he used his post as chief of staff to the attorney general to make a bid for a job as a United States attorney in Utah.

In many ways, until his resignation Monday, the rapid rise of Mr. Sampson, from a low-level aide on the Senate Judiciary Committee to one of the most senior advisers to Attorney General Alberto R. Gonzales, is like that of many other young, ambitious lawyers who come to Washington with a passion for politics.

He arrived in Washington in 1999, around his 30th birthday, with impeccable credentials  at least for a man his age  among religious conservatives. A native of Utah and a Mormon, he had completed his undergraduate studies at Brigham Young University. Mr. Sampson then followed the lead of Dallin H. Oaks, the former president of Brigham Young, by attending the University of Chicago for law school, another bastion of conservatism.

When President Bush was first elected, Mr. Sampson joined his transition team, helping screen nominees for judiciary or Justice Department jobs, said Taylor Oldroyd, a longtime friend. Mr. Sampson had learned about the nomination process from 1999 to 2001, when he worked for Senator Orrin G. Hatch, Republican of Utah, while he was chairman of the Judiciary Committee.