Updated at 7:15 p.m. ET
In an evening press conference, FBI Special Agent Tim Slater said investigators believe the suspect in the shooting Wednesday morning at a congressional baseball practice in Alexandria, Va., was living out of his van and had been in the area since March.
A gunman opened fire during an early morning baseball practice for Republican members of Congress, reportedly firing dozens of shots. Five people were hit with gunfire, including Majority Whip Steve Scalise of Louisiana.
Slater identified the shooting suspect as James Hodgkinson of Belleville, Ill. Hodgkinson, 66, was taken into custody at the scene of the shooting and transported to a hospital "where he succumbed to his injuries."
The FBI said it was not currently looking for other suspects, though Slater cautioned that he does not know where the investigation will lead. "We hope to answer motive, and why he was here, and why he did what he did," said Slater.
FBI agents are searching Hodgkinson's home in Illinois, he said. The suspect's vehicle was located on site and was swept by the Alexandria Police Department and the Bureau of Alcohol, Tobacco, Firearms and Explosives.
"Obviously we are looking to glean what we can from the contents of his [electronic] devices," said Slater. He said that they also hoped to learn where the suspect's handgun and rifle had come from, and who had purchased them.
Hodgkinson was a member of several online groups that took stances against Republicans and the president, the Belleville News-Democrat reports.
Five people were hit with gunfire in the incident Wednesday morning: Scalise, Special Agent Crystal Griner of the U.S. Capitol Police, congressional staffer Zachary Barth, Tyson Foods lobbyist Matt Mika, and the gunman. Rep. Roger Williams of Texas and Special Agent David Bailey of the U.S. Capitol Police sustained minor secondary injuries.
Griner was shot in the ankle, and is in good condition in the hospital, according to the U.S. Capitol Police.
Capitol Police officers are being widely praised for helping to stop the attack.
"Many lives would have been lost if not for the heroic actions of the two Capitol Police officers, who took down the gunman despite sustaining gunshot wounds during a very, very brutal assault," President Trump said shortly before noon.
The shooting occurred around 7 a.m. ET in the Del Ray area of Alexandria, just south of Washington, D.C., about 8 miles from Capitol Hill. A helicopter arrived to medevac at least one victim.
The FBI has taken over the investigation because the attack involved violence against a federal official.
The FBI is "exploring all angles" in the case, Slater said, responding to a question about whether the attack was an act of terrorism.
Federal investigators are conducting emergency traces on the two firearms, an ATF spokesman tells NPR's Carrie Johnson.
In the wake of the shooting, the House of Representatives canceled legislative business for the day, and security was increased around the White House. A public event that had been scheduled by Trump at the Labor Department on Wednesday afternoon was canceled.
Scalise was shot in the hip and underwent surgery at MedStar Washington Hospital Center. "Prior to entering surgery, the Whip was in good spirits and spoke to his wife by phone," Scalise's office said in a statement. "He is grateful for the brave actions of U.S. Capitol Police, first responders, and colleagues."
The hospital said Wednesday afternoon that Scalise was in critical condition.
Trump said in a tweet that Scalise "was badly injured but will fully recover," adding, "Our thoughts and prayers are with him."
The shooter opened fire at a baseball field at Eugene Simpson Stadium Park, across the parking lot from Alexandria's YMCA. Gunshots hit the YMCA's windows, and the building was shut down and the block cordoned off, NPR's Tom Bowman reported from the scene.
After receiving a call of shots fired at 7:09 a.m., officers arrived within three minutes, Alexandria Police Chief Mike Brown said. By 7:14 a.m., the FBI says "the subject was engaged by law enforcement and shot." At least two officers fired at the gunman, Brown added.
Rep. Mo Brooks of Alabama, who was at the practice, told CNN that the gunman was holding what he described as a semi-automatic rifle in the area behind third base and that Scalise had been near second base. Brooks told CNN that he tried to help Scalise, saying, "We used my belt to help put a tourniquet around his leg."
Two Capitol Police officers showed "incredible bravery," Brooks said, describing how they used their pistols to engage in a gun battle with a man armed with a rifle, from a distance of 90 to 120 feet.
Rep. Steve Pearce of New Mexico, who was at the practice but unharmed, tweeted prayers for the victims.
A local resident who posted a video of the scene after the shooting said, "There were probably about 80 to 100 shots fired over there."
That resident, Benjamin Childers, added, "We had three members of Congress [who] took shelter in our apartment."
Trump had issued a statement earlier:
"The Vice President and I are aware of the shooting incident in Virginia and are monitoring developments closely. We are deeply saddened by this tragedy. Our thoughts and prayers are with the members of Congress, their staffs, Capitol Police, first responders, and all others affected."
The shooting occurred the day before the Republican team is scheduled to play in the annual Congressional Baseball Game at Nationals Park. Pitting members of one party against another, the contest supports charities ranging from the Boys and Girls Clubs to the Washington Literacy Center.
Democratic Rep. Eric Swalwell of California said on Twitter that Thursday's game is still on.
Members of the Democratic Party's team were practicing elsewhere Wednesday morning; after the attack, they tweeted a photo of themselves taking a moment to think of their colleagues.
The violence disrupted what had been a quiet start to the day in Del Ray, hitting an area where many residents go to work out in the mornings and grab a coffee from a shop around the corner from the YMCA.
As NPR's Jessica Taylor reports from the neighborhood: "This is people going about their normal mornings, probably not even knowing that there were members of Congress that were practicing a few blocks down the road here. And it just went from really sort of a calm, peaceful morning to utter chaos in here."
This is a developing story. Some things that get reported by the media will later turn out to be wrong. We will focus on reports from police officials and other authorities, credible news outlets and reporters who are at the scene. We will update as the situation develops.