Heather Locklear was apprehended by police on suspicion of driving under the influence of an unknown controlled substance in theaffleunt Santa Barbara region, authorities stated Sunday. Locklear, 47, was forced over by a Calif. Highway police officer Saturday afternoon after a resident described witnessing the actress departing a parking area and "driving unpredictably," a police representative said. The police officer detected Locklear's automobile parked on a freeway and blocking off a lane in Montecito, an affluent residential area approximately ninety miles northwest of the City of Angels. "In communicating with her, the police officer decided that she appeared to be under the influence of something," Marshall alleged. Locklear was brought to the police headquarters, where she was screened for alcohol and drugs. Heather wastaken into custody at seven p.m. on suspicion of driving under the influence of prescription medicine. She was afterwards let go from being detained.