WASHINGTON — A 66-year-old Illinois man has been identified as the suspect in the shooting of a congressional baseball practice Wednesday, injuring at least one member of the House of Representatives.

James T. Hodgkinson allegedly opened fire at a field in Alexandria, Virginia, several law enforcement sources told NBC News. More than a dozen GOP lawmakers were there with staff.

The shooter then got into a gunfight with police, who shot him. He later died at a hospital, officials said. President Donald Trump paid tribute to the Capitol Police officers who likely saved lives in the face of a "brutal assault."

U.S. Sen. Bernie Sanders I-Vt. said in a statement he’d been told the shooter had "apparently volunteered" on his 2016 presidential campaign.

“I am sickened by this despicable act,” Sanders said. “Let me be as clear as I can be. Violence of any kind is unacceptable in our society and I condemn this action in the strongest possible terms.”

The law enforcement officials said the shooter was heard asking, "Are these the Republicans or the Democrats?" That has raised questions about the gunman's political motivations. But officials at the scene said that piece of the investigation remains unclear.

Hodgkinson, a licensed home inspector who ran his business out of his Illinois home, has a history of arrests, including a 2006 incident in which he allegedly pulled a gun on a man who went to his house to confront him about hitting the man's girlfriend.

The man accused Hodgkinson of hitting him in the head with the gun's wooden stock and, as he ran way, firing once without hitting the man, according to a police report. The girlfriend told police that the shooting was followed by a violent confrontation that also included Hodgkinson's wife and another woman. In the end, Hodgkinson was charged with domestic battery, battery and aggravated discharge of a firearm. But the case was later dismissed, according to public records.

The same day, another neighbor later told police, Hodgkinson damaged one of her bedroom doors during a search for his daughter, according to a police report. It is not clear how that case ended.

Police also responded to reports of gunshots at his Belleville home — about 20 miles southeast of St. Louis, Missouri — in late March, according to a police report. Callers to 911 reported hearing 50 shots. Police said they found Hodgkinson with a weapon in his possession and a valid Illinois firearms license. They told Hodgkinson not to fire his weapon in that area as there were homes nearby.

Hodgkinson, encountered on the property of his rural home with a high-powered rifle, told officers he was taking target practice. "He was very cordial, very nice, very understanding," St. Clair County Sheriff Richard Watson said Wednesday after speaking to one of the responding officers. "He had no reason to think he was doing anything illegal, immoral or anything."

Lyndon Evanko, who represented Hodgkinson in the 2006 case, described his former client as “an odd little guy” and “a bit of a misanthrope.”

“He wasn’t unpleasant. But he wasn’t particularly somebody you would want to hang out with. I got the feeling that he butted heads with a lot of people."

At the same time, Evanko said, Hodgkinson "didn’t seem the least bit political" or “somebody with a great deal of passion about anything."

Evanko added: “Had I not gotten the charge dismissed, he wouldn’t have been able to own a gun. I did my job a little too well.”

Dale Walsh, who described himself as a childhood friend of Hodgkinson’s, told reporters that he knew the shooter as "passionate in what he believed” but "in control."

“I never thought this would happen,” Walsh said.

Hodgkinson was a frequent writer to his local paper, the Belleville News-Democrat, where he railed against income inequality, linking it to the tax policies of the GOP, the newspaper reported.

"I have never said 'life sucks,' only the policies of the Republicans,' he wrote in one letter.

In another, Hodgkinson said his favorite TV program was "The Rachel Maddow Show" on MSNBC.

Hodgkinson’s Facebook postings portray him as stridently anti-Republican and anti-Trump.

"I Hate Republicans & everything they stand for," he wrote in December 2015. On June 3, he shared a caricature of the president as "Maximus Imbecilus." He was a member of several political Facebook groups, including one called "Terminate the Republican Party."

He also used a cartoon of Sanders as Uncle Sam as his profile picture.

A Sanders campaign staffer said Hodgkinson didn't play a significant role in the 2016 campaign.

Other law enforcement officials with knowledge of the investigation told NBC News that at this point there's no indication that the shooter had ties to international terrorism.

Witnesses said the gunman opened fire with a rifle from the third base side of the diamond.

One witness, David Thomas, said he had just left a YMCA gym when the shooting started. He said he saw the gunman pacing from one end of the third base dugout to the other, firing multiple rounds then stopping to shout things like "get out of here."

He briefly took cover with Laura Russell, then ran home, where she saw pictures of the gunman and recognized him as someone she often saw in the early morning at the YMCA working on a laptop. Russell said she never saw him working out, which she found odd. But "he was friendly," she said.

Two firearms, a rifle and a handgun, were recovered from the scene, the Bureau of Alcohol, Tobacco, Firearms and Explosives said.

The shooting also wounded two members of a dignitary protection unit of the U.S. Capitol Police.

The two officers were injured and are in good condition, officials said. The other reported victims, Rep. Steve Scalise of Louisiana, the House's majority whip, a congressional staffer and a lobbyist with Tyson Foods, were all expected to survive.

Pete Williams reported from Washington. Jon Schuppe, Tom Winter, Jonathan Dienst and Donna Mendell reported from New York. Chris Jansing reported from Alexandria.

CLARIFICATION (June 14, 1:50 p.m.):An earlier version of this article said that Hodgkinson was arrested in 2006 for assaulting his girlfriend. The nature of Hodgkinson's relationship with the victim is not clear.

PREVIOUS STORY: House Majority Whip Steve Scalise was among at least four people wounded Wednesday morning when a gunman opened fire during a congressional baseball practice at an Alexandria, Virginia, park. 

The Republican lawmaker was transported to MedStar Washington Hospital Center in Washington, D.C., where he was in stable condition and undergoing surgery. Scalise, 51, was injured in the hip. 

"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." 

Federal law enforcement officials identified the suspected shooter to NBC News as James T. Hodgkinson, 66, from Belleville, Illinois.

Two Capitol Police officers were also wounded and their injuries are not considered life-threatening. 

A statement from Congressman Roger Williams' office said the Texas Republican was not wounded, but a member of his staff — later identified as legislative correspondent Zack Barth — was shot and taken to the hospital. "Please keep the member of my staff and all members of the congressional baseball team in your thoughts and prayers," Williams tweeted. 

Alexandria Police Chief Michael Brown said five people were taken to local hospitals, including the suspect, following the shooting, which began shortly after 7 a.m. Brown declined to give conditions or identify the victims.

A spokeswoman for George Washington Hospital said two patients were brought to the facility and listed in critical condition, but declined further comment. 

Brown said officers at the scene returned gunfire with the suspect, who was eventually taken into custody and is no longer a threat. 

Multiple law enforcement officials with knowledge of the investigation told NBC News that there was no immediate indication that the shooter has ties to international terrorism. 

The Bureau of Alcohol, Tobacco, Firearms and Explosives said one rifle and handgun were recovered from the scene. Officials were trying to trace the ownership and purchase history of the two firearms in connection with the shooting, law enforcement sources told NBC News.

Rep. Mo Brooks, R-AL, said several other people also were hit, including two law enforcement officers. A staff member for Texas Congressman Roger Williams was injured, along with possibly another congressional aide. 

Brooks said that Scalise, 51, was down on the ground with what Brooks described as “a hip wound.” He was standing on second base when he was shot.

Scalise is the No. 3 House Republican leader. A congressional aide said Scalise was in stable condition at George Washington University Hospital.

Two Capitol Police officers were wounded and their injuries are not considered life-threatening. 

Police confirmed in tweets that it was investigating reports of a "multiple shooting" and that the suspect was "in custody" and "not a threat." The victims were being rushed to the hospital. 

According to Connor Ingram, Rep. Chuck Fleischmann was present at the time and he is ok. He was slightly injured as he attempted to flee the gunman.

According to multiple reports, a gunman opened fire at the baseball field. In addition to Rep. Scalise, NBC can confirm 2 Capitol police officers were also shot. They were on protective duty. There were several shots fired before police returned fire. 

According to Alexandria, VA police, a suspect is in custody. Alexandria is across the Potomac River from Washington, D.C. The shooting is Eugene Simpson Stadium Park, about 8 miles from the Capitol building.

The baseball team was preparing for the annual congressional baseball game where Republicans and Democrats form teams and play each other for charity. The game was scheduled to be played Thursday.

Alabama Congressman Mo Brooks is also a member of the GOP team. There's no word on his status.

President Trump expressed his concern via Twitter shortly afterward.

Rep. Steve Pearce of New Mexico tweeted that he was at the GOP's baseball practice and was "alright."

Both Democratic and GOP members of the House and Senate have been using the baseball field each morning in Alexandria's Del Ray neighborhood in preparation for a bipartisan game scheduled for Thursday. 

Sen. Rand Paul, who was at the batting cages at the field, told MSNBC that Scalise as a House leader always has Capitol Police with him as security detail. Scalise has represented Louisiana's 1st District since 2008. It was not immediately clear if the wounded officer was part of Scalise's detail. 

"There was a rapid succession of shots, you know five or 10 shots," Paul said. "In the field, I see Representative Scalise is shot but moving, and he’s trying to drag himself through the dirt and out into the outfield." 

"I probably heard 50-60 shots," Rand added. "Then finally we heard the response from the Capitol Hill police."