A former high-ranking Capitol Police official with knowledge of the department’s response to the Jan. 6 attack has sent congressional leaders a scathing letter accusing two of its senior leaders of mishandling intelligence and failing to respond properly during the riot.

The whistleblower, who requested anonymity for privacy reasons and left the force months after the attack, sent the 16-page letter late last month to the top members of both parties in the House and Senate. His missive makes scorching allegations against Sean Gallagher, the Capitol Police’s acting chief of uniformed operations, and Yogananda Pittman, its assistant chief of police for protective and intelligence operations — who also served as its former acting chief.

The whistleblower accuses Gallagher and Pittman of deliberately choosing not to help officers under attack on Jan. 6 and alleges that Pittman lied to Congress about an intelligence report Capitol Police received before that day’s riot. After a lengthy career in the department, the whistleblower was a senior official on duty on Jan. 6.

The whistleblower’s criticism went beyond Capitol Police leaders to Congress. Without naming specific lawmakers, his letter accuses congressional leaders of having “purposefully failed” to tell the truth about the department’s failures.

POLITICO obtained the letter detailing the allegations, which is circulating among Capitol Police officers, and is publishing portions of it here. To protect the whistleblower’s identity, POLITICO is not publishing the letter in full.

“The truth may be valued less than politics by many members of the congressional community to include those that have made decisions about the leadership of the USCP post January 6th, but I believe the truth still matters to real people and certainly the men and women of the U.S. Capitol Police,” the whistleblower wrote.

A spokesperson for the Capitol Police sent a statement in response to the letter that begins: “A lot has changed since January 6. Although there is more work to do, many of the problems described in the letter have been addressed.”

The spokesperson added that the department “has implemented, and continues to implement, many of the critical recommendations called for in” a Senate inquiry into Jan. 6, a separate review conducted by retired Lt. Gen. Russel Honoré, and multiple probes by its own inspector general...