Janesville Police were asked by Milwaukee Police to check out a tip that the 12-year-old may be located at 140 Ridge Creek Drive in Janesville. That's where police found her and 19-year-old Richard Rucks.
The runaway told officers she met Rucks over an internet dating site, and that the two had sex. It's unclear if Rucks knew the girl's age.
Rucks was arrested for 1st Degree Sexual Assault of a Child and is being held at the Rock County Jail. The 12 year old was returned to family members.