An internal investigation has cleared a U.S. Capitol Police officer of any wrongdoing in the fatal shooting of Ashli Babbitt during the siege of the Capitol on Jan. 6, the law enforcement agency announced Monday.

The Justice Department previously said the officer would not face criminal charges in the killing of the 35-year-old California woman, who was shot as she tried to force her way through a set of doors deep inside the Capitol.

Babbitt, who was the only Capitol rioter fatally shot by police, was praised by former president Donald Trump earlier this month. In a statement, Trump said he had questioned why the officer who shot her was “getting away with murder.” White supremacists and other far-right groups have labeled Babbitt a martyr.

The probe by the U.S. Capitol Police exonerated the officer for his use of force. The department said in a news release outlining the investigation that the officer’s actions were within department policy, which allows deadly force only when an officer reasonably believes they are protecting themselves or others from serious physical harm.

The department said it was not identifying the officer because he and his family have been the subject of numerous and specific threats. The department interviewed multiple witnesses, and also reviewed video and radio calls, before arriving at its decision, according to the release.

“The actions of the officer in this case potentially saved members [of Congress] and staff from serious injury and possible death from a large crowd of rioters who forced their way into the U.S. Capitol and to the House Chamber where members and staff were steps away,” the department wrote in the release.

Babbitt was among a mob of Trump supporters who used a flagpole, a helmet and other items to batter the barricaded doors to the Speaker’s Lobby, the hallway outside the House Chamber where some lawmakers were sheltering on the afternoon of Jan. 6.

Multiple cellphone videos captured Babbitt, who had a Trump flag draped around her neck like a cape, attempting to crawl through the shattered glass pane. The officer, who was standing on the far side of the doors, fired a single shot at her, sending her tumbling backward onto the floor.

Babbitt was hit in the shoulder and later died. Her slaying became a defining moment of the riot.

The Justice Department found in April that there was insufficient evidence to prove Babbitt’s civil rights had been violated and that it was reasonable for the officer to believe he was firing in self-defense or in defense of lawmakers fleeing the House chamber.

Mark E. Schamel, an attorney for the officer, said in a statement that the officer’s actions were “nothing short of heroic.”

“He stopped the final surge of rioters that were mere steps from members of Congress,” Schamel said. “It is not hard to imagine the impact on our democracy had these rioters been able to reach their intended targets: sitting members of Congress.”

Terrell N. Roberts III, an attorney for Babbitt’s family, said in an email that the Capitol Police should release a copy of the entire investigation so it can be reviewed by the public to determine if it was thorough, competent and fair.

“A one-sided inquiry behind closed doors proves nothing, and it certainly is not an ‘exoneration,’ ” Roberts wrote. “The world has already seen citizens’ videos of the shooting and has reached a different conclusion — one which is far from clearing the officer.”

In June, Babbitt’s family filed a lawsuit seeking more details about the officer who shot her and documents related to the investigation of the shooting.

Babbitt was a supporter of QAnon, an extremist ideology based on false claims, and an ardent backer of Trump, her since-deleted Twitter account showed. She tweeted support for Trump’s baseless claims that the 2020 election was stolen.

Babbitt also spent more than a decade in the military, and her ex-husband said she served in Iraq and Afghanistan.