CHICAGO (CBS) — Marking the one-year anniversary of the disappearance of a 6-year-old Aurora boy, police are seeking the public’s help to solve the mystery.

One year ago today, Amy Fry-Pitzen checked her then 6-year-old son Timmothy out of his Aurora elementary school before taking him on a two-day vacation and then taking her own life.

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Aurora Police are making a renewed appeal for northwestern Illinois land owners and residents to search their properties for several missing items that may help pinpoint what happened to the boy.

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Based on forensic testing of Fry-Pitzen’s SUV, investigators believe Amy stopped her vehicle in a meadow in Northwestern Illinois with Lee and Whiteside Counties as the most likely locations. However, areas in Carroll, Ogle, Stephenson, and Winnebago Counties cannot be ruled out, Aurora police said in a news release.

Missing items include Timmothy’s Spider Man backpack, several toys and a tube of toothpaste Amy had bought for Timmothy before he disappeared; and Amy’s cell phone and I-Pass device.

Investigators have no leads into Timmothy’s whereabouts including whether they boy is still alive or if he met with foul play. The also released surveillance video from the Kalahari water park in Wisconsin—as Amy and Timmothy checked out from the facility.

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Timmothy Pitzen would now be 7 years old. When he went missing, he was about 4 feet, 2 inches and weighed around 70 pounds with brown hair and brown eyes. Anyone who may have information is asked to call Aurora Police at (630) 256-5500, or their local authorities by dialing 9-1-1.