An Ohio gun store owner who listened to his gut and refused to sell a weapon may have prevented a shooting at Ohio University, police said.

A 25-year-old man looking to buy a rifle passed a background check at Downs Bait & Guns on Monday, but something didn’t feel right to owner John Downs, who chats with all customers at his Logan, Ohio, shop.

Though the sale was clear to go, customer James Howard was saying things that set off Downs’s alarm bells. The look on the young man’s face made Downs feel uneasy, like he knew something was wrong.

“I just said, ‘You know what, bud, I have a really bad feeling about this, I just can’t sell you the gun,’” Downs told Fox 28 News.

The decision turned out to be a good one.

When Downs turned Howard away, the 25-year-old began screaming and Downs called the police. “The owner advised that a male came in to purchase a firearm and was making statements that made the owner question his mental stability and the reason for purchasing the firearm,” police said. But by the time authorities got there, Howard was gone.

When Howard returned to the store later in the day, Downs called the police again. “I had some customers in here, put them all in a back room and I locked the door, turned the light out and shut my open sign off,” he said.

He didn’t know at the time that Howard had already purchased a weapon elsewhere.

“Apparently he was frustrated about something that happened at [Ohio University],” Hocking County Sheriff Lanny North told ABC 6. “I believe [Downs] did prevent a mass shooting that was probably going to occur at Ohio University in Athens.”

Unbeknownst to Downs, Ohio University police were already looking for the former student, who had withdrawn from all of his classes earlier in the day. Police say Howard walked into a university staff member’s office at the school’s Bird Arena on Monday and got into a physical altercation with the man. (Some reports indicate that Howard, a former hockey player, allegedly assaulted the team’s assistant coach.)

Police issued an arrest warrant for Howard after the alleged assault, according to a statement from Ohio University Police Department chief Andrew Powers. Meanwhile, Howard allegedly told a friend that he was going to buy a gun. He then drove to Downs’s store, and after being turned away, headed to another gun shop in Athens where he successfully purchased a weapon.

Deputies finally found him back in Logan, after locating his car in a Walmart parking lot. “Deputies located Howard inside the store at the firearms counter attempting to purchase a large quantity of ammunition, gloves and camouflage clothing,” the Hocking County Sheriff’s Department said. They reportedly found a weapon and other survival gear in Howard’s car.

The Athens Messenger reports that Ohio University was preparing to send a campus emergency alert at the time of the arrest.

“As concerning as these facts may sound, we have gathered no information so far to indicate Howard made any specific threats toward individuals or our campus in general,” Powers wrote.

According to Powers, Howard’s bond was raised to $125,000 after he was charged with a third felony count. Among the charges: burglary for the university assault, as well as a weapons charge because of a prior involuntary mental health hospitalization.

A university spokeswoman referred questions to the university police department.

But Downs—whose store has served the community for over 30 years, according to its website—hopes his calls will be able to help Howard as much as anyone else.

“I hope he gets the help he needs, apparently he does have something wrong with him and hopefully he gets some help,” he said.