Mr. Crapo, a Republican, was pulled over after his vehicle ran a red light, the police in Alexandria said. He failed field sobriety tests and was arrested about 12:45 a.m., said a police spokesman, Jody Donaldson, and then was taken to the Alexandria jail and released on an unsecured $1,000 bond about 5 a.m.       

“There was no refusal” to take sobriety tests, Mr. Donaldson said, and “no accident, no injuries.”       

“Just a traffic stop that resulted in a D.U.I.,” he said.