A former Nassau County school resource officer was sentenced Thursday afternoon to 20 years in prison followed by 10 years of sex offender probation for two counts of sexual battery involving a minor.

Alan Manchester, 47, pleaded guilty to the charges last month.

Last June, an investigation conducted by the State Attorney's Office revealed that Manchester had a sexual relationship with a girl beginning when she was 15 years old.

During that time, Manchester impregnated the girl, who is now 22, when she was 15 and 17 years old.