DARLINGTON COUNTY, S.C. (WBTW) — A Darlington County man will spend 13 years in prison after pleading guilty to sexually assaulting a young teenager he had been grooming for years, according to an announcement Friday morning from South Carolina Attorney General Alan Wilson.

Joseph James Williamson was sentenced after pleading guilty Wednesday to second-degree criminal sexual conduct with a minor.

Williamson was arrested after a 14-year-old’s mother found sexually explicit messages from the man on her daughter’s phone in 2019, according to the announcement. At the time, Williamson was 47 years old.

An investigation into social media accounts and the phone found more sexually explicit messages. He reportedly admitted he first sexually assaulted the girl in June 2019, and then again in late summer and fall.

Once released, he will be required to register as a sex offender.