U.S. Capitol Hill Police Chief Kim Dine briefs the media after shots were reported fired near 2nd Street NW and Constitution Avenue on Capitol Hill in Washington, D.C., on Oct. 3, 2013.

Miriam Carey is the female suspect in the shooting incident that left Capitol Hill on lockdown for a brief period Oct. 3, 2013.

A police car that struck a barricade blocks Constitution Avenue as U.S. Capitol Police investigate a possible shooting outside of the U.S. Capitol on Oct. 3, 2013 in Washington, D.C. Police called the matter an isolated incident, unassociated with any act of terrorism.

Capitol Hill police officers look at a car following reported gunfire near Capitol Hill in Washington on Oct. 3, 2013. A police officer was reported injured, police said. They locked down the entire U.S. Capitol complex, at least temporarily derailing debate over how to end a government shutdown.

A U.S. Capitol Police officer is taken to a Park Police helicopter after a shooting and police car crash on Constitution Avenue and 1st Street NW. The officer was injured in the car crash.

Rescue personnel stand around a smashed U.S. Capitol Police car following a reported shooting near the U.S. Capitol in Washington, Oct. 3, 2013. The Capitol went on lockdown on after the reports of gunshots fired outside the building.

The U.S. Capitol went on lockdown after reports of shots fired, Oct. 3, 2013.

A policeman runs after shots were reported fired near 2nd Street NW and Constitution Avenue on Capitol Hill in Washington, D.C., on Oct. 3, 2013. The U.S. Capitol was placed on security lockdown after the reported shots, senators said.

Capitol Hill police and medics take a victim away on a stretcher at the site of an apparent shooting, Oct. 3, 2013 on Capitol Hill in Washington, D.C. The U.S. Capitol was placed on security lockdown after shots were reported fired outside the complex, senators said.

Capitol Hill police officers respond to a possible shooting on Capitol Hill in Washington on Oct. 3, 2013. Police said the U.S. Capitol was put on a security lockdown amid reports of possible shots fired outside the building.

A member of the U.S. Secret Service looks out toward Lafayette Park from the roof of the White House in Washington, D.C., Oct. 3, 2013, following reports of possible gunfire near the U.S. Capitol.

People take cover as possible gunshots are heard at the U.S. Capitol in Washington, D.C., on Oct. 3, 2013. The U.S. Capitol was placed on security lockdown after the sound of possible gunfire, senators said. "Shots fired outside the Capitol. We are in temporary lock down," Sen. Claire McCaskill, D-Mo., said on Twitter.

People run for cover as police converge to the site of a possible shooting, Oct. 3, 2013 on Capitol Hill in Washington, D.C. The U.S. Capitol was placed on security lockdown after possible gunshots were reported outside the complex, senators said.

A man runs for cover as a police officer takes a shooting position at the site of a possible shooting Oct. 3, 2013 on Capitol Hill in Washington, D.C. The U.S. Capitol was placed on security lockdown Thursday after reports of possible shots fired outside the complex, senators said. Police were seen running within the Capitol building and outside as vehicles swarmed to the scene.

Capitol Hill police are seen at the site of a possible shooting Oct. 3, 2013 on Capitol Hill in Washington, D.C. The U.S. Capitol was placed on security lockdown after shots were fired outside the complex, senators said.

"Something happening outside Capitol. Police running around with guns at ready," was the caption to this Oct. 3, 2013 photo posted to Twitter.