Photo by Jacques Arsenault.

A shooting outside the U.S. Capitol, which prompted a lockdown Saturday afternoon, was a suicide, U.S. Capitol Police said.

Witnesses reported that there was a large crowd of tourists who witnessed the shooting on the western side of the Capitol. A lone man was carrying a sign that authorities described as bearing a message about social justice, as well as a backpack and a suitcase, which were investigated and cleared by a bomb squad.

Robert Bishop, who was standing nearby told CNN that there were about 50 or 60 people nearby who scrambled after hearing the gunshot. He said the sign had said something about taxing the 1 percent.

Most parts of the Capitol reopened within a few hours, though the Lower West Terrace remained closed through early Sunday morning.