Police cordon off the corner of the Contitution Ave and First St after shots fired were reported near 2nd Street NW and Constitution Avenue on Capitol Hill in Washington, DC, on October 3, 2013. The US Capitol was placed on security lockdown Thursday after shots were fired outside the complex, senators said. 'Shots fired outside the Capitol. We are in temporary lock down,' Senator Claire McCaskill said on Twitter. Police were seen running within the Capitol building and outside as vehicles swarmed to the scene.