Monday's deadly shootings at the Washington Navy Yard had Capitol Police carrying automatic weapons and sent the Senate into an early adjournment for the day, not long before the chamber issued an hours-long lockdown.
The moves were only precautionary, but they served as a stark reminder of the extreme security that can come into play at the Capitol, which has been both the scene of a shooting and the target of terrorist attacks in recent decades.
"Coming into the Capitol, I knew something was up, because I saw our police officers with their weapons, automatic weapons that they usually don't carry, at least in view of everybody on Constitution Avenue and other places," said Senate Majority Leader Harry Reid, D-Nev.
From the Senate floor, Reid, who was a Capitol Police officer while attending university (badge number 363, he recalled) and Minority Leader Mitch McConnell, R-Ky., praised law-enforcement officials and first responders before recessing.
"These kinds of incidents always remind us how fragile life is," McConnell said. "They also remind those of us who work in and around the Capitol how much we all owe to the men and women who work so hard to keep us safe every day."
Senate Sergeant at Arms Terrance Gainer placed the Senate complex on lockdown in the late afternoon. "Our immediate concern has been the unknowns," Gainer said in a statement. "Is this an act of workplace violence or something more sinister?"
House Speaker John Boehner, R-Ohio, also issued a statement. "This has been a dark day, and we know more of them lie ahead for the families of the victims. Hoping that they find comfort — and answers — is at the top of our minds," Boehner said in the statement. "Next, we ought to say 'Thank-you' to the first responders and law-enforcement professionals — including Capitol Police — who did their jobs and saved lives."
Yet the House did not lock down, which produced an at-times confounding security environment at the Capitol, with police offering conflicting directions about where staffers and others who work on the Hill could and could not go. A reporter trying to walk from the Senate side of the rotunda to the House side was stopped by police, but was permitted to move from chamber to chamber on the Capitol's third floor.
"It's a very fluid situation," one Capitol police officer said.
Beyond Monday's recess, the shooting also prompted the Senate Judiciary Committee to reschedule a hearing on stand-your-ground gun laws from Tuesday to Wednesday.
It's unclear exactly how many times either chamber of Congress has recessed because of a security threat like the one at the Navy Yard, according to the Senate historian's office. The House recessed in 2001 after an anthrax scare, but the Senate remained in session for several days, Associate Historian Betty Koed said.
Fifteen years ago, a lone gunman with a history of mental illness entered a first-floor entrance of the Capitol with tourists, then burst through a security checkpoint, shot and killed two officers, and bolted into nearby offices of then-House Republican Whip Tom DeLay. The 1998 rampage by Russell Weston Jr. jarred Congress to tighten security for the Capitol and surrounding areas. And three years later, the Sept. 11, 2001, terrorist attacks led to even tighter security.
As late as the 1990s, the area in and around the Capitol resembled a college campus or park, with much of that feeling owed to the redesign by renowned architect Frederick Law Olmsted in the 1870s. But today, the Capitol complex that includes the House and Senate office buildings, and the nearby Supreme Court and Library of Congress, has become a labyrinth of jersey barriers, blocked-off streets and building entrances, and traffic checkpoints. The security even extends underground. The Capitol Visitor Center, constructed and officially opened in December 2008 under the East Front plaza, now serves as the security screening funnel for visitors to the Capitol.
When Weston went on his deadly attack, there were about 1,200 Capitol Police officers. The force now includes 1,724 sworn officers (plus 353 civilian staffers), some equipped with more-powerful high-caliber weapons, night-vision capabilities, and better gear to protect themselves from bullets.
In addition, security systems and processes — such as magnetometers to detect metal objects — are now in place at building entrances, and emergency-evacuation measures are in place for the complex. Systems are also in place to safeguard electronic communications for Congress, and relocation drills are held regularly. Mail-screening processes have been moved to off-site locations to thwart the use of regular mail to deliver deadly chemicals.
Of course, Weston's attack — and the failed targeting of the Capitol on 9/11 — certainly weren't the only times in history that violence has threatened the building. In 1814, British forces set fire to the Capitol. In 1835, President Andrew Jackson was almost assassinated outside the Capitol rotunda. And in 1954, four Puerto Rican nationalists wounded five lawmakers when they fired guns from the visitors' gallery above the House floor.
Still, it wasn't so long ago when the grounds surrounding the building seemed much more open. Hill residents and tourists could jog or sightsee freely around the outside balconies and steps, enjoying spectacular views of the mall or just relaxing. Not anymore.