A Modesto man has been arrested for having an unregistered handgun in Santa Rosa. Early Sunday morning, police on foot patrol in Downtown Santa Rosa approached a driver sitting in a parked car on the 200 block of Fifth Street. They searched the vehicle and found a Glock semi-automatic .45-caliber handgun in the trunk of the car along with a large quantity of cannabis. Police arrested 38-year-old Aurielo Merino-Mendez for being in possession of an unregistered firearm.