Who are the unidentified officers?

Many of the officers whose agencies aren’t identifiable by markings on their uniforms are from federal Bureau of Prisons tactical teams. They normally respond to riots behind bars, where, officials said, the agency they work for is understood and such markings are generally unnecessary. As the violence escalated, Mr. Barr temporarily empowered the bureau to make arrests in the continuing protests, according to a law-enforcement official. The bureau said in a statement that its officers are highly trained and capable in such scenarios.

“I probably should have done a better job of marking them nationally as the agency,” Bureau of Prisons Director Michael Carvajal said Thursday. “But I assure you no one was specifically told, to my knowledge, not to identify themselves.”