Republican lawmakers were practicing for the annual congressional baseball game.
Flake said the suspect was a white man with dark hair, apparently in his 40s or 50s, wearing jeans and a blue shirt, while Brooks added that there appeared to have been only one attacker.
The top Republican and Democratic leaders in the U.S. House of Representatives, often at sharp odds over contentious government policies, joined Wednesday in a common plea for humanity in the immediate aftermath of a gunman's attack on a congressman and four others at a baseball field.
Indiana's congressional delegation is thanking the Capitol Police for its work in the shootout which injured House Majority Whip Steve Scalise.
"Gayle and I are sending our thoughts and prayers to congressman Scalise, aides and Capitol Police officers who were injured today and their families".
But the White House quickly cleared Mr Trump's schedule of political events and prepared remarks that could have been made by nearly any president. "Pray for Steve!" Trump wrote in a tweet yesterday. The popular and gregarious lawmaker is known for his love of baseball and handed out commemorative bats when he secured the No. 3 job of House whip several years ago. Then, members of Congress paid tribute to Giffords for eight hours on the House floor, and both sides pledged to temper their rhetoric as they waited for Giffords to return.
During an interview on CNN's "Erin Burnett OutFront", Alabama Rep. Gary Palmer was asked if he thought the team was targeted because they were Republicans, to which he replied "I believe we were", before pleading with the country to come together after this tragedy.
Four others were also shot, including the suspected gunman, James Hodgkinson of IL, who died of his wounds.
"Their sacrifice makes democracy possible", he said.
After Wednesday's shooting, some lawmakers said they would look into having more security when they gather in large numbers. Some of the most indelible images of Barack Obama's presidency followed an act of violence, including the tears in his eyes while mourning the 26 people, including children, killed in Newtown, Connecticut, in 2012 and his rendition of "Amazing Grace" while delivering a eulogy after nine churchgoers were killed in Charlestown, South Carolina, three years later. "Thankful, as always, for the U.S. Capitol Police and all they do".
"He's loyal to the person he's assigned to protect", Brooks said of the officer. "The Congressional Baseball Game for Charity is scheduled for 7:05 p.m., tomorrow night, June 15".
Speaking after the shooting Mr Sanders, the former candidate for the Democratic presidential nomination, said that Hodgkinson had apparently volunteered for his campaign a year ago.
"This is like the first, like really like breaking, breaking news that I've ever like gotten to cover, so I wish it hadn't been something where people got hurt." she said. Giffords was shot in the head by Jared Lee Loughner at a "Congress On Your Corner" event at a Tucson grocery store.