The preliminary investigation pertaining to the death of US Capitol rioter Ashli Babbitt has not found enough evidence to criminally charge the police officer who shot and killed her, officials say.

According to officials, the investigation conducted by the Metropolitan Police Department was not complete, and the US attorney’s office had not received a recommendation to prosecute the officer.

Babbit, 35, who served for more than a dozen years in the Air Force and Air National Guard, participated in one of a handful of mob attacks that nearly reached members of Congress during the hour-long siege of the Capitol on January 6.

The Capitol police officer shot and killed Babbitt as she tried to jump the barrier in an attempt to enter the speaker’s lobby through a broken window.

The fatal encounter was caught on video and was heavily circulated on social media, showing that the unnamed lieutenant was left to face the mob alone.

The officer had been placed on administrative leave immediately after the riot as the investigation over Babbitt’s death commenced.

The U.S. attorney’s office in Washington is currently leading a wide-range investigation of the riot, leading to the prosecution of more than 150 cases to date.

Dustin Sternbeck, the spokesperson for the Metropolitan Police Department, said “it would be premature” for the department “to make any comment that any conclusion had been reached.”

A Justice Department spokesperson said that a formal, federal excessive force investigation of Babbitt’s death was opened days after the Capitol riot.

Lethal force is considered a legally justified act if an officer has an “objectively reasonable” fear of serious harm to themselves or others.

Babbitt’s death resulted in her becoming a martyr-like figure for the far-right extremist groups that have supported former President Donald Trump.