Robbery Investigation Leads To Discovery Of Firearms Bay City News Service FacebookTwitterEmail CASTRO VALLEY (BCN) Deputies investigating a pharmacy takeover robbery in Castro Valley on Friday uncovered a large cache of weapons, the Alameda County Sheriff's Office said. The robbery was reported at the Walgreens store at 3382 Castro Valley Blvd. Deputies located a car similar to the one used in the robbery parked at a storage unit facility, officials said, and contacted the driver, whom they found was armed and on probation. A search of the suspect's storage locker turned up at least seven firearms, including one reported as stolen. "Some were stolen (AK Pistol) and the handguns are full auto with 100 round drums," the office said in a social media post.