Hours after the news conference, Pittman released a statement identifying the officer who had been killed as William Evans.
Acting Metropolitan Police Chief Robert Contee said there wasn't an ongoing threat and the attack didn't appear to be terrorism-related.
President Joe Biden, who is spending the weekend at Camp David, was briefed on the incident, the White House said. The suspect was shot after getting out of the vehicle with a knife.
Per the DC Fire and EMS scanner, three individuals were picked up from Capitol Hill, including two police officers. Another officer has been injured. The suspect died at a hospital.
But CBS News reported that security officials had already warned congressional staffers of a threat before the auto ramming. The law enforcement officials told the AP that the driver then got out of the vehicle with what appeared to be a knife. It's unclear which member of law enforcement shot the suspect.
The police also notified road closures "due to the external security threat at the North Barricade of the US Capitol".
Officials initially said the suspect was being taken to the hospital in critical condition. But the hallways were mostly empty despite the chaos outside.
The most recent was the January 6 riot that saw large crowds of supporters of former President Trump storm the building while Congress was in a joint session to certify President Biden's Electoral College victory. National Guard troops who have guarded the building since then were seen mobilizing around the area of the incident.
"At this time, the suspect has been pronounced dead", Acting U.S. Capitol Police Chief Yogananda Pittman told reporters. The officials spoke to AP were not authorized to publicly discuss the pending investigation and spoke on condition of anonymity.