The flags flying at half mast over the U.S. Capitol Monday morning were not the only indications of the assassination attempt on Rep. Gabrielle Giffords in Tucson, Ariz., this weekend.
There was a increased, visible security presence on Capitol Hill today as members of Congress and hundreds of congressional staffers observed a moment of silence in honor of Rep. Gabrielle Giffords, D-Ariz., and those who were killed and wounded two days ago in Tucson.
Well-wishers and mourners left flowers and candles at a makeshift tribute which was surrounded by velvet ropes on the east front of the Capitol in the shadow of the Statue of Freedom, which adorns the dome.
As the moment of silence approached, streams of staffers poured out of the House office buildings across Independence Avenue towards the Capitol.
U.S. Capitol police officers asked staffers to present their identification before they were permitted to join the gathering. Other officers with high-powered rifles marched back-and-forth scoping out any potential threats. Even more officers patrolled the grounds on foot and bicycles.
About a dozen members of Congress joined the large staff gathering for the one minute of silence. By the time they finished lining up, the steps were packed shoulder-to-shoulder.
After the somber moment passed, Rep. Emanuel Cleaver, D-Mo., asked everyone to put their arms around one another to join in prayer.
"Help us move from this dark place to a place of sunshine and hope," Cleaver prayed. "Bless these God, our servants, who serve this nation. Keep them safe. More than anything God we ask that you keep our hearts pure."
Hours after the tragic attack Saturday, Cleaver told ABC News that incidents like the Giffords shooting should not prevent members of Congress from meeting with constituents, as the Arizona Congresswoman was doing at the time of the shooting.
"If we're going to be a representative government, and we are in the House of Representatives, we've got to put anything in the back of our minds that would prevent us from interacting with our constituents," Cleaver said.
But some members said today they do not want heightened security measures to come between themselves, and their constituents.
"We virtually go back, at least I do, virtually every weekend with lots of public events, whether going to the grocery store or to church, I mean, people know what we're up to in the communities that we represent and I see that very unlikely to change," Rep. Fred Upton, R-Mich., said. "In reality, you would really change the way that we operate if you impose such a new set of restrictions and for the most part I think most of us would balk it."
"I will not be paralyzed by fear. I will not look at my citizens and automatically think that I am in danger," Rep. Hank Johnson, D-Ga., proclaimed. "I walk with my chest held high, my head held high, and I know that I am responsible for everything I say and do."
"I am not concerned and if I were I don't see how I could be a member of the House of Representatives. Our mandate is to get as close to the people as possible," Del. Eleanor Holmes Norton, D-D.C., added. "We stand for election every two years, because the people have to judge us up close."
Nevertheless, today many people on Capitol Hill were on edge.