At about 1:10 p.m., detectives conducted a probation search at the home of 46-year-old William Kevin Sanford, in the 6400 block of state Highway 12 in Santa Rosa. Sanford was on probation for possession of illegal drugs, sheriff's officials said.
During the search, Sanford was found to be in possession of an illegal, loaded, high-powered assault weapon with numerous high capacity magazines. Detectives also found two other rifles, a shotgun, a handgun, and numerous rounds of ammunition.
According to sheriff's officials, Sanford is a convicted felon and therefore prohibited by law from owning a firearm.
Sanford was arrested and booked into the Sonoma County Jail. He is being held on $30,000 bail, sheriff's officials said.