Stephen James Brown, 72, entered Farr's satellite office in the Santa Cruz County Government Building Monday and offered to take a staffer to lunch -- but then made threats after his offer was declined, police said.
The Santa Cruz County Sheriff's Office, housed in the same building as Farr's office, increased security and issued an alert to locate Brown.
Brown was arrested several hours later at a nearby military recruiting office, the Santa Cruz Sentinel reported.
Farr was in Washington at the time, but offered a statement commending his staff "for being able to calmly defuse the situation."
Brown was jailed, and investigators determined he had no bomb-making materials and was not following through on his threat, the newspaper said.