LOUISVILLE, Ky. (WHAS11) -- The Louisville man who used Facebook and Backpage to sell a girl for sex and was arrested for human trafficking a minor has decided not to fight federal charges.

After several delays federal prosecutors gave Silky Clark an ultimatum this week: take the deal or his case goes to trial.

Clark took the deal.

He pleaded guilty in federal court to charges including the production of child pornography and sex trafficking of a minor.

Although the terms of the plea deal remain sealed, the father of the victim in the case told us Clark will have to serve 20 years in prison.

Clark, who is now 40, used social media, including Facebook, as well as the defunct website Backpage to market a 16-year old for sex.

Police rescued the girl, who they say they found high on drugs, from Clark's apartment in Louisville.

Clark wrote to WHAS11 from jail claiming he didn’t realize the girl was a minor and that she lied about her age, however the girl’s father claims Clark knew she was underage after he and Clark messaged back and forth on Snapchat.

The girl’s father said he also plans to be at Clark's sentencing on August 12th.