This is an archived article that was published on sltrib.com in 2011, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Prosecutors filed rape and sexual abuse charges Friday against a 36-year-old Salt Lake City man accused of assaulting a 12-year-old girl.

Robert D. Thornton was charged in 3rd District Court with three counts of rape of a child, three counts of sodomy upon a child, three counts of aggravated sexual abuse of a child — all first-degree felonies— and one count of tampering with a witness, a third-degree felony.

Police discovered the abuse when an officer went to the home of the girl's mother to check on the child's welfare on Dec. 31, according to charging documents. The Tribune is not naming the mother to protect the girl's identity.

The officer arrested Thornton and the mother, 33, on outstanding warrants, but the mother escaped after she was handcuffed. When a detective interviewed the girl, she said her mother had given her the prescription drugs Valium and Klonopin "to try." She also told the detective that for the "past few months," Thornton had been having sex with her and forcing her to perform oral sex two or three times, according to charging documents. He allegedly said he would "kill her if she told anyone."

The mother, who is still at large, was charged with endangerment of a child and escape, both third-degree felonies.