Capitol buildings were placed on lockdown Monday afternoon after reports surfaced of a gunman opening fire at or near the U.S. Capitol Vistor Center. At a news conference Monday evening, police said the suspect never fired his weapon but drew it during the screening process to get inside the visitor center.

“During a routine screening (the suspect) drew what appeared to be a weapon and pointed it at officers,” Capitol Police Chief Matthew Verderosa said.

At least one officer shot the suspect. Authorities later recovered a weapon on the scene, although officials did not elaborate on what kind of weapon it was.

The suspect's condition was not immediately known. Police declined to identify him, although Verderosa said investigators believe he was known to law enforcement.

Police located the suspect's vehicle on Capitol grounds, where they seized it pending a search warrant.

Authorities believe Monday's incident was the “act of a single person who has frequented the Capitol grounds before, and there is no reason to believe this is anything more than a criminal act,” Verderosa said.

Contrary to initial reports, police said no officers were shot. Verderosa confirmed, however, that a bystander was injured. Police did not identify the bystander but said she is a woman between 35 and 45 years old. Her injuries appeared to be minor, Verderosa said.

The lockdown on most Capitol buildings was lifted around 3:50 p.m. The Capitol Vistor Center remained closed as officers investigated the crime scene.

All Capitol buildings were placed on lockdown at 2:45 p.m. due to a "potential security threat." Workers were told to shelter in place. The White House also was put on lockdown briefly.

Video from the scene showed chaos in the moments after the lockdown was put in place.

Visitors were being turned away from the Capitol as emergency vehicles flooded the street and the plaza on the building's eastern side. Police, some carrying long guns, cordoned off the streets immediately around the building, which were thick with tourists visiting for spring holidays and the Cherry Blossom Festival.

Traffic was jammed in the vicinity, but despite the obvious emergency the scene was relatively calm. A work crew on the north side of the Supreme Court, across the street, was asked to stop work and move away from the building as a precaution.