PALMER PARK, Md. >> A Maryland man who called himself “a joker” and had an arsenal of semi-automatic rifles threatened to shoot up the business from which he was being fired and was wearing a T-shirt that read “Guns don’t kill people. I do,” when first confronted by officers, police said Friday.

The man, identified in a search warrant as Neil E. Prescott, told a supervisor at software and mailroom supplier Pitney Bowes that, “I’m a joker and I’m gonna load my guns and blow everybody up,” and that he wanted to see the supervisor’s “brain splatter all over the sidewalk,” according to a police officials and a search warrant.

The threats were made two times in separate phone calls this week, and investigators who searched the 28-year-old’s apartment Friday morning found several thousand rounds of ammunition and about two dozen semi-automatic rifles and pistols. He was receiving a psychiatric evaluation at a hospital and charges were pending Friday.

“We can’t measure what was prevented here, but was going on over the last 36 hours was a significant incident in the county. And we think a violent episode was avoided,” said Prince George’s County Police Chief Mark Magaw. The workplace that Prescott is accused of threatening to shoot up is located in the county, just outside Washington.

It wasn’t immediately clear when the threat was to be carried out or how seriously it was meant to be taken, but last week’s mass shooting at a Colorado theater during the latest Batman movie — coupled with the “Joker” reference — put police especially on edge and gave the comments extra urgency, officials said.

“In light of what happened a week ago in Aurora Colo., it’s important to know, (for) the community to know, that we take all threats seriously. And if you’re going to make a threat, we will take action,” Magaw said.

Though there’s no other indication of a link to the Colorado shooting, police believe the joker comments Prescott made were a “clear reference” to the killings, the warrant says. The man accused in those shootings, James Holmes, had his hair dyed reddish-orange as if out of a comic book, and New York Police Commissioner Ray Kelly has said he also called himself the Joker, though Aurora police have not confirmed that.