An off-duty CSO observed a male taking parts from a bicycle at the Castro Valley Station. Officers were dispatched and they detained the male. The male claimed he owned the bike he was removing parts from but had no proof to verify his story. A records/warrant check revealed the male had a prior conviction of theft. The male was place under arrest for theft with priors. A search of his backpack revealed additional bicycle parts and burglary tools. Detectives was notified of the case and responded to the station. The male was booked at Santa Rita Jail for theft.