A convicted sex offender from Rio Nido was to be arraigned today on suspicion of possessing illegal knives, a half-pound of marijuana, driving with a suspended license, giving false information to an officer and violating parole, CHP officials said.

Robert McDowell, 42, was considered an armed and dangerous parolee-at-large by the Sonoma County Sheriff's Office because he failed to register as a sex offender, CHP Officer Jon Sloat said.

A pickup's broken tail light led CHP Officer Shawn Harvey to pull McDowell over at 3 p.m. Saturday on Santa Rosa Avenue near Court Street, Sloat said.

On Monday, McDowell was being held without bail at the Sonoma County Jail.