Darlington police arrested Tommy McCall, 61, Tuesday for Criminal Sexual Conduct with a four-year-old boy.
Sergeant Kim Nelson says the child's grandmother contacted them and they started an investigation.
After an forensic interview with the four-year-old, officers obtained warrants to charge McCall, according to Sgt. Nelson.
McCall tried to have sex with boy sometime between June 1 and October 26, Nelson said.