Gunfire on Capitol Hill

A police officer, with gun in position, keeps watch after a report of shots fired outside the Capitol in Washington.  (Alex Leary / Associated Press)

A view of a car involved in a shooting on Capitol Hill.  (Brendan Smialowski / AFP/Getty Images)

A crashed black car sits after a shooting incident near the U.S. Capitol in Washington. A motorist attempted to get through security barriers near the White House and was chased to the Capitol, where shots were fired, according to reports citing the US Secret Service.  (Michael Reynolds / EPA)

Police are posted outside the U.S. Capitol as the area is secured.  (Shawn Thew / EPA)

Police rush into position on Capitol Hill after shots were fired outside the Capitol in Washington, D.C.   (Jewel Samad / AFP/Getty Images)

Tourists flee the Capitol area as police survey the scene after shots were fired.   (Mandel Ngan / AFP/Getty Images)

People take cover as gunshots are heard at the U.S. Capitol in Washington. The Capitol was placed on lockdown Thursday after shots were fired outside the complex, senators said.   (Jewel Samad / AFP/Getty Images)

Capitol Hill police and medics take a shooting victim away on a stretcher on Capitol Hill in Washington.  (Mandel Ngan / AFP/Getty Images)

People run after hearing gunshots near the U.S. Capitol in Washington.  (ShawnThew / EPA)

A man runs for cover as a police officer takes a shooting position at on Capitol Hill in Washington.   (Mandel Ngan / AFP/Getty Images)

Police gather on Capitol Hill in Washington after shots were reported fired near 2nd Street NW and Constitution Avenue.   (Brenden Smialowski / AFP/Getty Images)