Steven W. Mier, 157 Third St., Apt. 6, is in the Fond du Lac County Jail.
The girl, who police say is a runaway from Madison, was hiding in a closet of the apartment when the Fond du Lac Police Department’s Sex Offender Compliance Team (SOCT) assisted Probation and Parole during a routine check at about 9 p.m.
The SOCT is a group of police officers who work with the Wisconsin Department of Corrections to routinely check on registered sex offenders in Fond du Lac to assure they are complying with regulations.
On Nov. 16, 1999, Mier, 29, was sentenced in Calumet County to eight years in prison on one count of second-degree sexual assault of a child, according to the Wisconsin Circuit Court Web site.
Police also found explicit photos of children on his cell phone, Klein said.
“I think this just shows how effective the Sex Offender Compliance Team can be,” Klein said. “This is exactly why we have these guys out there checking on these (sex offenders) to make sure they are compliant.”