Officers responded to 481 Rosemont Drive at about 5:35 p.m. Thursday on a report of suspicious circumstances at the address, and officers heard what sounded like a BB gun being fired in the home.
Police said that officers negotiated with Daniel Pappas, 45, to come out of the home and arrested Pappas without incident. Officers learned that Pappas allegedly had been firing a .22-caliber rifle from inside the home.
After obtaining a search warrant, police detectives found give blowguns, four improvised explosive devices, three homemade guns and hundreds of rounds of ammunition, police said.
The Santa Clara County Sheriff's Office Bomb Unit responded to the home and found that two of the explosive devices were unstable and disposed of them on site. The other two devices were taken for further study.
Pappas was booked into Santa Clara County Jail on suspicion of possession of explosive devices and negligent discharge of a firearm, as well as for weapons-related violations.
