Quick action by Fond du Lac Police credited in sexual assault/child abduction suspect being captured just hours after going missing

Quick action yielded quick results Monday, January 27, 2025, when a man, convicted for attempted child abduction and sexual assault of a child, cut off his GPS house arrest monitoring bracelet and went M.I.A.

The days events started early afternoon when Fond du Lac Police were notified that Chad Maertz cut off his monitoring system which disrupted the ability to be tracked by authorities.  A check of his residence in the city of Fond du Lac at 99 W. Division Street showed he wasn’t there.

Fond du Lac Police quickly issued a statement on their social media indicating what happened and provided a photo of Maertz and his vehicle description. That post spread like wild fire through the social media platforms and calls started coming in to the department with sightings.

One call in particular was an important lead as it indicated Maertz may have switched vehicles. A caller indicated they saw Maertz in a white Hyundai car with Minnesota plates. The plates came back to a local car rental business. A Fond du Lac Police Officer confirmed with the business that Maertz did indeed rent that vehicle and the plates were entered into the Flock Camera system.

Later that afternoon, the plates hit on a Flock Camera in Germantown where officers there quickly canvassed the area, finding the vehicle in a Walmart parking lot. Officers assembled into a group and began searching the area and found Maertz in the Walmart, taking him into custody without incident.

Maertz was convicted in 2003 of attempted child abduction stemming from his attempt to abduct a 16-year-old Campbellsport girl while she was riding her bike in 2002.

He was also convicted in 1987 of two counts of sexual assault of a child in Washington County.

In those cases, Maertz grabbed a six-year-old girl and put her into his car and took her to his house where he had sexual contact with her before returning her to the neighborhood where he had picked her up. The second offense occurred three months later when Maertz enticed an eleven-year-old girl onto the roof of a school to retrieve a baseball. When she got to the roof, Maertz grabbed her, removed her clothes and engaged in sexual contact.

It’s unknown when Maertz was released from prison and placed on the GPS monitoring bracelet.