Investigators recovered a gun from the abandoned car of mass shooting suspect Robert Card, multiple law enforcement sources told ABC News.

Card's white Subaru was found Wednesday night.

Authorities are testing and tracing the gun to determine if it was involved in the shooting, according to multiple law enforcement sources.

Card may have access to other firearms. Sources said law enforcement is treating him as though he is armed and dangerous.

-ABC News' Luke Barr

The shooting unfolded in part during youth night at a local bowling alley. Witnesses described a desperate scene where people hid behind benches and tables and even inside the bowling pin machine at the end of a lane.

Meghan Hutchinson, who was at the bowling alley with her daughter said, "When I turned around, I saw the shooter. ... I don't know if that was just a warning shot or if he shot somebody with that [bullet]."

"Between the lanes there's some swinging doors where they keep all the mechanical stuff out back, so we kind of all just ran that way," she said. "We barricaded in there and another parent was in the room with me. She had a phone, she called 911."

Her daughter, 10-year-old Zoey Levesque, was grazed by a bullet.

"I never thought I'd grow up and get a bullet in my leg," she said. "Like, why do people do this? I was more worried about, like, am I going to live and going to make it out of here? Like, what's going to happen? Are the cops going to come?"

The family of mass shooting suspect Robert Card is cooperating with authorities, law enforcement officials briefed on the investigation told ABC News.

The family is laying out an account of a deeply troubled person, the sources said, bolstering earlier accounts of mental health treatment, voices in his head and alleged threats to shoot up a National Guard facility.

Card's sister told investigators she thought Card might have been looking for an ex-girlfriend at the shooting locations: a bowling alley and a bar, the sources said.

The U.S. Coast Guard is searching the Kennebec River in Maine for any sign of the mass shooting suspect, Robert Card.

Card owns a boat and property in the Lewiston area, according to a source briefed on the situation.

"Currently, one response boat crew from Station Boothbay Harbor, and an Air Station Cape Cod HC-144 fixed wing aircraft are assisting with patrols," Coast Guard spokesperson Rob Simpson said in a statement.

U.S. Rep. Jared Golden, (D-ME), announced that he was changing his policy against an assault rifle ban during a news conference with other Maine congressional leaders Thursday evening.

Golden was one of five Democratic House members who voted against a ban in 2022. Although the bill passed 217 -213, it did not move forward in the Senate.

Golden said the shooting has made him change his stance and will now support any measures in Congress that ban assault weapons.

"I ask for forgiveness and support as I seek to put this end to these terrible shootings," he said.

Sen. Susan Collins, (R-ME), told reporters that although she wanted to see more gun control reforms, such as a ban on high-volume magazines, she did not support an assault rifle ban.

Although Collins said she didn't know the circumstances as to how the suspect, who has had reported mental health issues, was able to commit the shooting, she said more should have been done.

She cited the state's "yellow flag" law, which gives law enforcement the authority to request a court to remove firearms from someone who has mental health problems.

"It certainly seems that on the basis of the facts that we have, the yellow flag law should have been triggered," she said.