Upland police officers responded at about 2 a.m. to the 500 block of West Arrow Highway, where the driver crashed into several parked cars, authorities said.
Through an investigation, officers determined the driver was driving under the influence of alcohol, and he was arrested for DUI-related charges.
Upland police confirmed the driver of the vehicle is an off-duty law enforcement officer from an outside agency, though it's unclear what department he belonged to.
Anyone with more information regarding the incident is urged to call the Upland Police Department at (909)946-7624.