Updated August 23, 2021 at 5:03 PM ET

The officer who shot and killed rioter Ashli Babbitt during the Jan. 6 insurrection at the U.S. Capitol acted within department policy, the U.S. Capitol Police announced on Monday.

"After interviewing multiple witnesses and reviewing all the available evidence, including video and radio calls, the United States Capitol Police has completed the internal investigation into the fatal shooting of Ms. Ashli Babbitt, which occurred in the Speaker's Lobby on January 6," the department said in a statement.

"USCP's Office of Professional Responsibility (OPR) determined the officer's conduct was lawful and within Department policy, which says an officer may use deadly force only when the officer reasonably believes that action is in the defense of human life, including the officer's own life, or in the defense of any person in immediate danger of serious physical injury."

The officer, who is not being named to protect the officer's safety, will not face disciplinary action from the department.

The Capitol Police's decision comes after the Justice Department in April said it would not pursue charges against the officer who fatally shot Babbitt as she attempted to breach a barricaded, shattered glass door leading to the House chamber.

The attorney representing the officer hailed the department's decision and said "the nation owes the lieutenant a tremendous debt of gratitude" for his work defending the Capitol that day.

"This decision by the USCP's Office of Professional Responsibility to exonerate the Lieutenant, like the decisions of the Department of Justice and United States Attorney's Office for the District of Columbia, is the only correct conclusion following the events of January 6th," the attorney, Mark E. Schamel, said in a statement.

"Every piece of evidence that is released further validates the Lieutenant's conduct. The Lieutenant exercised professionalism and restraint in heroically defending and protecting members of Congress and their staff during the violent insurrection on January 6th."

Since Babbitt's death, the far right has painted the rioter as a martyr who was felled by a system intent on villainizing Trump supporters.

The department has faced a flurry of calls to identify the officer who fired the fatal shot, including from within the Congress among lawmakers the officers are sworn to protect.

"Six months ago today, Ashli Babbitt, a 110-pound woman with nothing in her hands, not a rock, not a stick or a bat, was shot dead by a still unknown Capitol Hill police officer," Arizona Rep. Paul Gosar said in a statement on the six month anniversary of the insurrection.

Law enforcement has also faced criticism within progressive circles for failing to thwart — and by some video evidence, seeming to welcome — the horde of violent Trump supporters.

On the issue of transparency, the Capitol Police are "the worst I've seen," according to Daniel Schuman, policy director for the group Demand Progress, and Babbitt's widower told NPR in May that he plans to sue the Department of Justice in part to get more information about the shooting.

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