The U.S. Capitol Police said the chief of staff to Speaker Mike Johnson was arrested on suspicion of drunken driving on Tuesday night after the top aide backed his car into a parked Capitol Police vehicle.

The arrest came soon after President Trump, with Mr. Johnson presiding behind him, finished delivering his first address to a joint session of Congress since returning to office.

“A driver backed into a parked vehicle last night around 11:40 p.m.,” a Capitol Police spokesman said in a statement. “We responded and arrested them for D.U.I.”

Mr. Johnson’s office confirmed on Wednesday that Hayden Haynes, the speaker’s chief of staff, was involved in an “encounter” with Capitol Police on Tuesday night, releasing a statement that indicated that he would continue to hold his powerful post.

“The speaker has known and worked closely with Hayden for nearly a decade and trusted him to serve as his chief of staff for his entire tenure in Congress,” Taylor Haulsee, Mr. Johnson’s spokesman, said in a statement about the arrest, which was reported earlier by NBC News. “Because of this and Hayden’s esteemed reputation among members and staff alike, the speaker has full faith and confidence in Hayden’s ability to lead the speaker’s office.”

Mr. Haynes was released with a citation, rather than taken to jail, and would have a court date “within the coming weeks,” according to the Capitol Police. Since drunken-driving cases in Washington, D.C., are prosecuted by the district’s attorney general rather than the U.S. district attorney’s office under the Justice Department, the Trump administration would have no apparent role in the case.