Last Updated Jun 15, 2017 11:47 AM EDT
A gunman carrying a riflewhere members of Congress were practicing in Alexandria, Virginia, Wednesday morning, shooting three people and wounding one other before being taken into custody.
The gunman, identified as, later died of his injuries.
Among the injured was Louisiana Republican Rep. Steve Scalise, who was shot in the hip and taken away on a stretcher. He underwent surgery on Wednesday and remains in the hospital in critical condition as of noon Thursday.
Two Capitol Hill police officers in Scalise's security detail, a congressional staffer and a lobbyistin the attack.
Scalise, 51, serves as majority whip in the House of Representatives, the third-highest leadership position in the Republican conference. He represents Louisiana's first congressional district, which includes portions of New Orleans.
Reaction poured in fromafter the shooting Wednesday, representing a rare moment of bipartisan unity in the capital. Scalise's colleagues hoped for a speedy recovery and praised his courage in the face of the attack.
"Steve, in his own way, may have brought some unity to our long divided country," President Trump said at an event Thursday.
Scalise has been in Congress since 2008, when he replaced Bobby Jindal, who surrendered his seat as governor. Prior to winning election to his House seat, Scalise served in the Louisiana legislature, first in the House and then briefly in the state Senate.
Before becoming majority whip, Scalise served as the chairman of the Republican Study Committee, the leading caucus of conservative members.
In June 2014, Scalise was elected as majority whip by his fellow Republicans after a series of events stemming from then-House Majority Leader Eric Cantor's defeat in a primary to a conservative challenger. Scalise had the solid backing of conservative members, including many Southerners.
Scalise came under intense criticism in December 2014 after revelations that he had delivered a speech to a white supremacist group in 2002 before being elected to Congress. Scalisefor addressing the organization, saying "it was a mistake I regret, and I emphatically oppose the divisive racial and religious views groups like these hold."
His fellow Republicansas Democrats called on Scalise to resign his leadership post. Then-Speaker John Boehner called Scalise "a decent man" who had "made a mistake." Scalise was eventually re-elected as majority whip in January 2015 as the new session of Congress convened.
More recently, Scalise played a key role in Republican efforts to repeal and replace Obamacare, helping shepherd the American Health Care Act through the House after an initial failure to bring the bill to a vote.
Scalise is a strong supporter of gun rights and the Second Amendment, earning an A+ rating from the National Rifle Association. He has cosponsored legislation to loosen gun restrictions in Washington, D.C., and expand recognition of concealed carry permits.
Scalise, who is Catholic, is a Louisiana native and graduated from Louisiana State University in 1989. He and his wife have two children and live in Jefferson, Louisiana, according to his House biography.