U.S. Capitol On Lockdown After Reports Of Gun Shots(01 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Police work an active scene at the U.S. Capitol October 3, 2013 on Capitol Hill in Washington, DC. The US Capitol and the White House were placed on lockdown after an \'active shooter\' situation was reported. (Photo by Mark Wilson/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(02 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Police work an active scene at the U.S. Capitol October 3, 2013 on Capitol Hill in Washington, DC. The US Capitol and the White House were placed on lockdown after an \'active shooter\' situation was reported. (Photo by Mark Wilson/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(03 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Police work an active scene at the U.S. Capitol October 3, 2013 on Capitol Hill in Washington, DC. The US Capitol and the White House were placed on lockdown after an \'active shooter\' situation was reported. (Photo by Mark Wilson/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(04 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Police close in on the U.S. Capitol as people run for cover after reports of a shooting October 3, 2013 on Capitol Hill in Washington, DC. The US Capitol and the White House were placed on lockdown after an \'active shooter\' situation was reported. (Photo by Alex Wong/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(05 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Police work an active scene at the U.S. Capitol October 3, 2013 on Capitol Hill in Washington, DC. The US Capitol and the White House were placed on lockdown after an \'active shooter\' situation was reported. (Photo by Alex Wong/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(06 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Law enforcement and rescue personnel respond to an incident on Constitution Avenue outside the U.S. Capitol October 3, 2013 in Washington, DC. Capitol police locked down the facility during the incident. (Photo by Win McNamee/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(07 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: FBI agents in SWAT gear respond to reports of shots fired at the U.S. Capitol. October 3, 2013 in Washington, DC. Capitol police locked down the facility during the incident. (Photo by Win McNamee/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(08 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: U.S. Capitol police respond to reports of shots fired at the U.S. Capitol. October 3, 2013 in Washington, DC. Capitol police locked down the facility during the incident. (Photo by Win McNamee/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(09 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Police attend to injured person at the U.S. Capitol October 3, 2013 on Capitol Hill in Washington, DC. The US Capitol and the White House were placed on lockdown after an \'active shooter\' situation was reported. (Photo by Alex Wong/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(10 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: U.S. Capitol police respond to reports of shots fired at the U.S. Capitol. October 3, 2013 in Washington, DC. Capitol police locked down the facility during the incident. (Photo by Win McNamee/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(11 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Law enforcement personnel respond to reports of shots fired at the U.S. Capitol. October 3, 2013 in Washington, DC. Capitol police locked down the facility during the incident. (Photo by Win McNamee/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(12 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Jeff Flake (R-AZ) looks out the window at the U.S. Capitol October 3, 2013 on Capitol Hill in Washington, DC. The US Capitol and the White House were placed on lockdown after an \'active shooter\' situation was reported. (Photo by Mark Wilson/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(13 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: U.S. Capitol police respond to an incident on Constitution Avenue outside the U.S. Capitol October 3, 2013 in Washington, DC. Capitol police locked down the facility during the incident. (Photo by Win McNamee/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(14 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Law enforcement personnel gather around a police vehicle that was involved in an incident with another vehicle on Constitution Avenue outside the U.S. Capitol October 3, 2013 in Washington, DC. Capitol police locked down the facility during the incident. (Photo by Win McNamee/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(15 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Law enforcement personnel gather around a police vehicle that was involved in an incident with another vehicle on Constitution Avenue outside the U.S. Capitol October 3, 2013 in Washington, DC. Capitol police locked down the facility during the incident. (Photo by Win McNamee/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(16 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: FBI agents in SWAT gear respond to an incident on Constitution Avenue outside the U.S. Capitol October 3, 2013 in Washington, DC. Capitol police locked down the facility during the incident. (Photo by Win McNamee/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(17 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Law enforcement personnel respond to an incident on Constitution Avenue outside the U.S. Capitol October 3, 2013 in Washington, DC. Capitol police locked down the facility during the incident. (Photo by Win McNamee/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(18 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Law enforcement personnel respond to an incident on Constitution Avenue outside the U.S. Capitol October 3, 2013 in Washington, DC. Capitol police locked down the facility during the incident. (Photo by Win McNamee/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(19 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Law enforcement personnel respond to an incident on Constitution Avenue outside the U.S. Capitol October 3, 2013 in Washington, DC. Capitol police locked down the facility during the incident. (Photo by Win McNamee/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(20 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Capitol Police enforce the lockdown at the U.S. Capitol October 3, 2013 on Capitol Hill in Washington, DC. The US Capitol and the White House were placed on lockdown after an \'active shooter\' situation was reported. (Photo by Mark Wilson/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(21 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Law enforcement personnel respond to an incident on Constitution Avenue outside the U.S. Capitol October 3, 2013 in Washington, DC. Capitol police locked down the facility during the incident. (Photo by Win McNamee/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(22 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: A police officer checks out a car on grass with his canine near the U.S. Capitol October 3, 2013 on Capitol Hill in Washington, DC. The US Capitol and the White House were placed on lockdown after an \'active shooter\' situation was reported. (Photo by Mark Wilson/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(23 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Sen. Bernie Sanders (I-VT) speaks on the phone at the U.S. Capitol October 3, 2013 on Capitol Hill in Washington, DC. The US Capitol and the White House were placed on lockdown after an \'active shooter\' situation was reported. (Photo by Alex Wong/Getty Images) (credit:Getty Images)
U.S. Capitol On Lockdown After Reports Of Gun Shots(24 of24)
Open Image ModalWASHINGTON, DC - OCTOBER 03: Sen. Bernie Sanders (I-VT) speaks on the phone at the U.S. Capitol October 3, 2013 on Capitol Hill in Washington, DC. The US Capitol and the White House were placed on lockdown after an \'active shooter\' situation was reported. (Photo by Mark Wilson/Getty Images) (credit:Getty Images)