A DUI driver with a handgun has been arrested in Santa Rosa. Early Sunday morning, an officer pulled over a Ford Mustang for a vehicle code violation on the 200 block of Orange Street. The officer suspected the driver, 23-year-old Antonio Lopez, was driving under the influence. A search of the car turned up a loaded semi-automatic handgun, one that wasn’t registered to Lopez. He was arrested on various DUI and firearm related charges.