WASHINGTON, D.C. ? Carl J. Truscott resigned Friday as director of the Bureau of Alcohol, Tobacco, Firearms and Explosives amid an inquiry into spending on the agency’s new headquarters.

A former senior official with the Secret Service, Truscott was picked by then-Atty. Gen. John Ashcroft in April 2004 to head ATF, which has about 5,000 employees, half of them agents.

His tenure was marked by complaints from within the agency that he was spending too much time and money on the agency’s new headquarters building about a mile north of the Capitol, particularly at a time of tight budgets. The building is supposed to open later this year.

Justice Department Inspector General Glenn A. Fine earlier this year began investigating complaints that Truscott approved or proposed additional spending on the building and other projects.