San Luis Obispo police say 62-year-old Richard Orcutt was taken into custody early Sunday and a search of his home found several handguns, rifles, shotguns and thousands of rounds of ammunition.
A police statement says an arrest warrant for Orcutt was issued after detectives investigated letters sent to property managers and homeowners in the area.
Orcutt was booked into the San Luis Obispo County Jail for investigation of criminal threats and hate crimes. Bail was set at $500,000.
It is unclear if he has an attorney. There was no telephone listing for Orcutt in San Luis Obispo or the surrounding area.