A Los Angeles County Sheriff’s Department deputy has pleaded no contest to having a sexual relationship with a 15-year-old girl whom he met while on duty at the Marina del Rey station.

Kenneth Alexander, 46, pleaded no contest Aug. 10 to an amended count of oral copulation of a person under 18, said Deputy District Attorney Andrea Thompson of the Sex Crimes Division. Alexander is scheduled to be sentenced before Judge Mark Windham Aug. 29.

The deputy was arrested Oct. 20 when he turned himself in to authorities at the sheriff’s station in Carson.

He met the 15-year-old girl while he was working on duty at the Marina Sheriff’s station in 2010 and responded to an investigation at her home, a district attorney spokeswoman said.

The suspected relationship occurred when the deputy met with the girl off-duty in View Park between Aug. 10, 2010 and Feb. 28, 2011, according to the criminal complaint.

Alexander, who remains free on his own recognizance, faces five years formal probation, 60 days in county jail and one year of sex offender treatment, the district attorney spokeswoman said.