A motorist rammed a car into US Capitol police on Friday and brandished a knife, killing one officer and injuring another and forcing the Capitol complex to lock down in an attack that police said did not appear to be terrorism-related, Reuters reported.

Police shot and killed the suspect.

Yogananda Pittman, acting chief of the US Capitol Police, said the suspect drove into the officers, then hit a barricade and got out of the vehicle, lunging at them with a knife.

One of our officers has succumbed to his injuries. Police identified the slain officer as William “Billy” Evans, an 18-year veteran of the force.

Officials said the other officer was in a stable and non-life threatening condition.

“It does not appear to be terrorism-related, but obviously we’ll continue to investigate,” said Robert Contee, acting chief of the Metropolitan Police Department of Washington.

President Joe Biden said he was heartbroken by the attack and ordered flags at the White House be lowered to half-staff.

Multiple media organizations, citing anonymous sources, named the suspect as Noah Green, 25, of Newport News, Virginia. Green’s brother told the Washington Post that his sibling struggled with drug use and paranoia and his family worried about his mental state.

According to media reports, Green spoke on Facebook about the “end times”, the anti-Christ, and government “mind control”. He also said he was unemployed after leaving his job, “partly due to afflictions,” and praised Nation of Islam leader Louis Farrakhan.

Facebook said in a statement that it removed the suspect’s accounts from Facebook and Instagram and were in contact with law enforcement.

Police said the suspect was not known to them, and they had yet to determine what motivated him.