Kash Patel, the F.B.I. director, has been removed as the interim head of the Bureau of Alcohol, Tobacco, Firearms and Explosives and replaced by Daniel Driscoll, the Army secretary, four people with knowledge of the switch said on Wednesday. The highly unusual move places a civilian military leader in charge of a domestic law enforcement entity.
White House officials decided to make the switch in late February, just after Mr. Patel was named the A.T.F.’s director, because the responsibilities of running two agencies was seen as too time-consuming, according to an official briefed on the situation. Mr. Driscoll was selected because he was one of the few Senate-confirmed Trump appointees available to take over, the person said.
Mr. Driscoll, an Iraq war veteran who is close to Vice President JD Vance, learned over the past week that he was being handed the reins of the small, embattled federal agency responsible for enforcing the nation’s gun laws, officials said.
Mr. Driscoll was traveling in Germany on Wednesday and was not immediately available for comment. But a Defense Department official confirmed that Mr. Driscoll had assumed interim leadership of the A.T.F. with very little notice in recent days. The official did not know exactly when Mr. Driscoll had assumed his new additional duties.
A Justice Department spokesman did not immediately respond to a request for comment.
The decision was announced to the A.T.F.’s supervisors on Wednesday morning. It left many of the agency’s staff members stunned and concerned that the switch would mean a significant recalibration of their mission at a time when hundreds of firearms investigators have been diverted to support immigration enforcement efforts.
While the appointment of Mr. Patel, a former Trump campaign surrogate, to run the A.T.F. was viewed with skepticism, the offloading of a component agency of the Justice Department to a Pentagon official is something entirely new.
The move comes at a moment of chaos at a largely leaderless and rudderless A.T.F.
Mr. Patel has spent most of his time running the F.B.I. and the Justice Department has proposed merging the A.T.F. with the Drug Enforcement Administration, a plan that has left the gun agency’s career leadership demoralized. That move, however, is unlikely to take place anytime soon.
Some fear that the plan to merge the D.E.A. and the A.T.F. might be a pretext for gutting both agencies, two of the smallest and most underfunded entities in the Justice Department. The replacement of Mr. Patel is unlikely to improve morale.
This week, Attorney General Pam Bondi, under pressure from gun rights groups, announced plans to eliminate the A.T.F.’s “zero tolerance” policy, put in place four years ago, that strips the federal licenses of firearms dealers found to have repeatedly violated federal laws and regulations, people briefed on the move said.
Ms. Bondi also ordered Mr. Patel to review two other major policies enacted under the Biden administration, with an eye toward scrapping both. One is a ban on so-called pistol braces used to convert handguns into rifle-like weapons, and the second is a rule requiring background checks on private gun sales.
Eric Schmitt contributed reporting.