In a news release, the Justice Department said that the investigation did not find evidence that the officer had violated any federal laws and that there was nothing to contradict that he believed it was necessary to shoot at Babbitt, 35, "in self-defense or in defense of the Members of Congress and others evacuating the House Chamber."
"Officials examined video footage posted on social media, statements from the officer involved and other officers and witnesses to the events, physical evidence from the scene of the shooting, and the results of an autopsy," and "based on that investigation, officials determined that there is insufficient evidence to support a criminal prosecution," the release said.
The investigation found that "Babbitt was among a mob of people that entered the Capitol building and gained access to a hallway outside 'Speaker's Lobby,' which leads to the Chamber of the U.S. House of Representatives. At the time, the USCP was evacuating Members from the Chamber, which the mob was trying to enter from multiple doorways," it said.
The statement gave a harrowing account of what the officer, who was not identified, faced.
"Members of the mob attempted to break through the doors by striking them and breaking the glass with their hands, flagpoles, helmets, and other objects. Eventually, the three USCP officers positioned outside the doors were forced to evacuate. As members of the mob continued to strike the glass doors, Ms. Babbitt attempted to climb through one of the doors where glass was broken out," the statement said.
The officer "fired one round from his service pistol, striking Ms. Babbitt in the left shoulder, causing her to fall back from the doorway and onto the floor," the statement said. "A USCP emergency response team, which had begun making its way into the hallway to try and subdue the mob, administered aid to Ms. Babbitt, who was transported to Washington Hospital Center, where she succumbed to her injuries."
The Justice Department said the focus of the investigation was to determine whether the officer violated any federal laws, including federal criminal civil rights laws.
It said that in federal court, "evidence that an officer acted out of fear, mistake, panic, misperception, negligence, or even poor judgment cannot establish the high level of intent required" under the law. The announcement said Babbitt's family had been notified that the case is closed.
Babbitt, an Air Force veteran, was a decorated security forces controller who served multiple Middle East tours from 2004 to 2016, according to Air Force records.
Babbitt was a loyal Fox News Channel watcher, according to thousands of tweets to Fox News hosts, and she engaged on social media with the conspiracy site Infowars. Last year, she began to tweet with accounts and hashtags associated with QAnon. The day before the rally, she tweeted: "Nothing will stop us....they can try and try and try but the storm is here and it is descending upon DC in less than 24 hours....dark to light!"
Babbitt was one of five people, including a Capitol Police officer, to die as a result of the riot.
More than 300 people have been charged with taking part in the riot, which happened as a joint session of Congress was tallying the Electoral College vote count.