Inside a modest brown and white corner house on a quiet Santa Clara street, Daniel Pappas was accumulating a dangerous stash of homemade weapons and explosives, police said Saturday.

Pappas, 45, was arrested Thursday evening after police arrived at his house to respond to reports of “suspicious circumstances,” including reports he was firing a .22-caliber rifle, Sgt. Ray Carreira said.

Police found homemade guns, four improvised explosive devices, blowguns and hundreds of rounds of ammunition once they coaxed Pappas out of the house on Rosemont Drive, negotiating with him after hearing what sounded like a BB gun being fired inside.

Officers later discovered that Pappas had been firing a .22-caliber rifle inside the home, Carreira said.

A woman, whose identity was not disclosed, was in the home at the time but was not injured, according to police.

Carreira could not explain why Pappas was hoarding the homemade weaponry.

Saturday afternoon, a middle-aged woman answered the door at the house on the intersection of Rosemont Drive and Pruneridge Avenue, declining to discuss Pappas.

John Phillips, a next-door neighbor, said Pappas appeared to have some mental instability and health issues but didn’t appear to be a threat.

“He didn’t bother me,” said Phillips, who was aware his neighbor had rifles but surprised to learn of the homemade explosive devices. “I let him ramble on about his flying saucers and aliens.”

Santa Clara police arrived at Pappas’ house at 5:34 p.m. Thursday. Detectives obtained a search warrant and during their search of Pappas’ house late Thursday and early Friday found the illegal weaponry, including two explosive devices deemed so unstable they could not be transported out of the house safely.

The Santa Clara County sheriff’s bomb squad was called in to dispose of those two devices at the home. Two other devices were removed and are being examined, Carreira said.

Santa Clara police did not release further details on the homemade bombs, saying only they could be ignited.

Carreira said Pappas was booked on weapons charges, possession of explosive devices and negligent discharge of a firearm. As of Saturday night, Pappas was still in custody in the Santa Clara County Jail.

Contact Howard Mintz at 408-286-0236