Police and agents from the FBI and ATF said they were moving cautiously at the home in the 8000 block of Oakhurst Place because there were indications of booby traps.
"Officers and agents will be donning their bomb suits, they will be walking in there, they'll be using robots also to go into areas that they don't feel are safe," said ATF agent Christian Hoffman.
The discovery was made while authorities were inspecting the home of 46-year-old William Hunziker, who was arrested Tuesday after reports that he had been firing a gun in his front yard. He was taken into custody on suspicion of elder abuse when a woman in his care appeared to be in need of medical attention due to severe malnutrition.
"He's just a good old man," said Chris Davidson, a friend of the suspect who arrived to the scene of the investigation. "He's just a man who had his little quirks. Now it seems they're making him out to be some kind of Unabomber."
Authorities said the investigation at the home was suspended Wednesday evening until morning due to the lack of daylight.