The gunman, identified by law officials as James Hodgkinson, died after the shootout. But federal police officials continue to investigate the incident, which shook Washington and stirred calls for unity from Capitol Hill.
President Donald Trump, accompanied by first lady Melania Trump, made a hospital visit on Wednesday evening.
Here's a list of five victims who were injured in the attack, and what we know about their conditions so far.
The House majority whip, 51, is a five-term Republican from Louisiana.
He is an avid baseball fan and has played on the congressional baseball team since he entered Congress in 2008.
Scalise was in critical condition after suffering damage to internal organs, and his injuries will require additional operations, according to a MedStar Washington Hospital Center medical update late Wednesday.
"Congressman Steve Scalise sustained a single rifle shot to the left hip. The bullet traveled across his pelvis, fracturing bones, injuring internal organs, and causing severe bleeding," MedStar said in a statement put out by Scalise's office. "He underwent immediate surgery, and an additional procedure to stop bleeding. He has received multiple units of blood transfusion. His condition is critical, and he will require additional operations. We will provide periodic updates."
Mika, a former congressional staffer, is a lobbyist for Tyson Foods.
He was out of surgery but remained in critical condition as of Wednesday afternoon, according to a statement from his family.
The congressional staffer, who works for Rep. Roger Williams of Texas, was shot in the leg and has since been released from the hospital.
"He was in the outfield," Williams said about Barth during a news conference on Wednesday. "I give him credit. All the time he was bleeding, we were under fire. He was texting -- he was texting letting people know we were under fire and that we needed help. So, he's doing great. Vice President (Mike) Pence has spoken to him. I'm grateful for that."
Griner, 32, is also a Capitol Police special agent.
In a statement, Capitol Police said Griner was in "good condition in the hospital, having been shot in the ankle."
Bailey is a Capitol Police special agent who is part of the congressional security detail.
He "was treated and released having sustained a minor injury during the incident," Capitol Police said in a statement.
Rep. Roger Williams
Rep. Roger Williams, 67, of Texas sustained a leg-ankle injury.
The former minor-league baseball player has coached the GOP Congressional team since 2013, his office said.
Williams will travel to Texas after Thursday's game tomorrow to have his doctor look at his injury.