Gunman shoots 4 inside Walmart, dies from self-inflicted gunshot: Police

Four people were injured after a man walked into a Walmart in Ohio with a rifle and began shooting, police said.

Authorities said the incident happened around 8:36 p.m. ET on Monday in Beavercreek, about 10 miles southeast of Dayton.

The shooter was found dead in the store from an apparent self-inflicted gunshot wound around 8:42 p.m. by a responding officer, Beavercreek police said.

The victims were transported to area hospitals, three in critical condition and a fourth with non-life-threatening injuries, police said. One victim remains in critical condition as of Tuesday afternoon while the rest are stable, police said.

All four victims -- three women and one man -- were shopping in the store at the time of the shooting, police said.

The suspected shooter was identified by Beavercreek police as 20-year-old Benjamin Charles Jones of Dayton.

"The FBI is currently looking at the shooter, his background, his motivation," Zrinka Dilber, the assistant special agent in charge for the FBI's Cincinnati Field Office, told reporters during a press briefing on Tuesday. "We are very, very early in this process."

Beavercreek Mayor Bob Stone applauded the quick response to the shooting, saying it "undoubtedly saved lives and minimized the impact of this devastating event."

"It's always one of those things where you don't think it can happen in your community. So anytime it does, it's shocking. It's tragic," acting Beavercreek Police Chief Capt. Chad Lindsey told reporters.

Walmart issued a statement to ABC News, saying those at the company were "heartbroken."

"We're heartbroken by what's happened at our Beavercreek, Ohio store," the company's statement read. "This remains a developing situation, and we're working closely with investigators on the scene."

The Bureau of Alcohol, Tobacco, Firearms and Explosives; the Ohio Bureau of Criminal Investigation; the FBI and other local agencies were on the scene Monday night assisting Beavercreek police with the investigation.

ABC News' Matt Foster, Darren Reynolds and Sasha Pezenik contributed to this story.