Agents in protective gear are searching for explosives in cluttered conditions at a Riverside home Thursday after a woman in her 80s was found living there Wednesday in squalor and a man was arrested on suspicion of discharging a firearm in the front yard.
The man, identified as 46-year-old William Laurence Hunziker, is scheduled to appear in court Thursday. He was booked on suspicion of discharging a firearm in a negligent manner and possession of a silencer, according to jail records.
His bail amount is listed at $1 million.
Police received a call Tuesday at about 2 p.m. warning of a man discharging a gun in the front yard of a home in the 8200 block of Oakhurst Place (map). Officers took the man into custody and found a woman -- neighbors said they believe she is Hunziker's mother -- living in squalor.
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Officers also uncovered "items indicative of explosives" Wednesday at the home.
Agents and a bomb squad robot returned to the location early Thursday. Weapons and items that tested positive for explosive materials were found in the home, Riverside police said.
"Some things were in plain sight," said Lt. Guy Toussaint, of the Riverside Police Department. "Now we're looking to make sure there aren't things hidden."
Investigators with the Bureau of Alcohol, Tobacco and Firearms and FBI were at the home until sunset on Wednesday. Officers remained at the location overnight, but called off the search because of darkness.
The search will be a "very slow process," authorities said.
"When you're dealing with high explosives and explosive material, there's always the risk of heat, friction, shock and ultra-violet rays that can set off an explosive," said Christian Hoffman, special agent with the Bureau of Alcohol, Tobacco and Firearms. "Depending on where the items were in the house, it could make the difference between it being a safety hazard and risk to the public. If they're in a place than can be bumped or shock can hit them or light can hit them, it could set the high explosives off.
"We're going room to room. You have to watch the items you pick up and move."
Several items were destroyed in a controlled detonation on the property Thursday morning. The controlled detonations were expected to continue into Thursday afternoon.
Agents told NBC4 Wednesday night they discovered a system designed to alert people inside the house when someone was on the property. Conditions in the home -- authorities described it as "hoarder-like" -- required agents to remove items before examining areas.
"This is similar to hoarder-type conditions," said Toussaint. "The more clutter, the more physically dangerous it is for our operators."
The agents are using robots and wearing protective gear as they search the home.
Neighbors were evacuated during the investigation Wednesday. Three nearby homes will be evacuated during the Thursday search.
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