The Napa County Sheriff's bomb squad detonated six pipe bombs at a Vallejo residence and police arrested the 61-year-old resident for possession of explosive devices and materials Thursday evening, a Vallejo police lieutenant said.
This was the second time in three days the Napa County bomb squad was called to detonate potentially dangerous explosives.
Tuesday in the noon hour, the bomb squad set a counterexplosion to neutralize the hazard posed by a half-century-old case of ether discovered at the Napa County Fairgrounds in Calistoga.
You can watch a video of the explosion here:
WATCH: Fireball in Calistoga as Bomb Squad Detonates Ether
The Napa bomb squad was also called to Vallejo Aug. 1:
Napa Bomb Squad Detonates Grenade in Vallejo
In Thursday's incident, approximately 100 homes in the area of 3700 Georgia Street were evacuated, and an after-school class at nearby Hogan High School, located behind the residence, was dismissed, Lt. Sid DeJesus said. Residents returned to their homes after 10 p.m. Thursday, DeJesus said.
Police went to the residence around 1 p.m. after "developing information" about the resident, Keith Allen Oliveira, DeJesus said.
"His activities came to our attention and we had immediate surveillance," DeJesus said.
A SWAT unit arrived around 3 p.m., and the Napa County Sheriff's Department's bomb squad detonated six fully-functional pipe bombs outside the residence around 6 p.m., De Jesus said.
Oliveira was arrested around 6 p.m. He told police making the explosive devices was a hobby, DeJesus said.
"The guy had a very strange hobby and a rudimentary knowledge on how to make pipe bombs," DeJesus said.
Oliveira was booked on suspicion of possessing material with the intent of making explosive devices and possession of a destructive device near a school, both felony offenses, DeJesus said.
Police also seized materials used to make explosive devices, DeJesus said.
By Bay City News Service. Napa Patch editor Louisa Hufstader contributed to this report. For the latest reports on explosions, fires and police activity, please see our Police & Fire section, available from the News tab above and at napavalley.patch.com/police-fire.