Federal agents in Washington state have arrested an armed man accused of making threats against President Obama via e-mail.

Federal agents took Anton Caluori, 31, into custody on Tuesday afternoon, Secret Service spokesman Brian Leary said. Caluori reportedly came to door with a shotgun but was taken into custody without injury, Leary said.

Secret Service Assistant Special Agent in Charge Bob Kierstead told local ABC news affiliate KOMO that suspicious items, including potential explosive devices, were found in the man’s apartment, which prompted a bomb squad to search the premises. No bombs were found.

“He has a good education, he’s a good boy, but he’s done a stupid thing,” Caluori’s mother, Renee told KOMO. “I don’t know a whole lot. How would you feel if your son got arrested? Never got arrested, was in the military, has a college education. And I’m just a little bit upset and shocked.”

Obama, who was campaigning in Ohio at the time, did not appear to be in immediate danger.

“A threat against the president was delivered via email to a general FBI inbox,” said Cathy Schrock, who works with the Washington police. “The Secret Service went down to investigate, and the defendant was found to be armed when they arrived at the apartment.”

Caluori is currently in federal custody and will have an initial court appearance Wednesday afternoon, sources said. He is accused of threats against the president and assaulting a federal officer.