Thomas J. Sadler, 47, was arrested without incident Thursday afternoon at his Santee home.
Sadler, who has been a member of the department for 20 years, reportedly was on duty and driving his assigned, unmarked vehicle, last February when he pulled up alongside a prostitute who was sitting on a bus bench on El Cajon Boulevard. He reportedly ordered the woman to get into his car and the two drove to Camino Del Rio South in Mission Valley, near the intersection of Interstates 8 and 805, and parked. Police allege that he then fondled the woman's genitals and breasts.
Three witnesses reportedly viewed the incident and made a 911 call to report a kidnapping was taking place.
The woman later called police that she spotted the deputy and took down his plate number. When police went to question Sadler, who has not yet been arraigned, he reportedly refused to cooperate.
Sadler was later identified by the woman and two others in a photo lineup.