Police search new area for missing 6-year-old Timothy Pitzen

(CBS/WBBM/AP) AURORA, Ill. - Police have started searching western Illinois for 6-year-old Timothy Pitzen, because it's where investigators say his mother used a cell phone to call friends and family to tell them she and her son were safe.

Pictures: Missing 6-year-old Timothy Pitzen

Timothy has been missing since Friday, when his mother, Amy Fry-Pitzen, was found dead inside a Rockford, Ill. motel room after apparently slitting her wrists.

Police have started to post photos of Timothy at rest stops and gas stations close to the Illinois-Iowa border, reports CBS station WBBM.

The last time anyone saw Timothy was Friday afternoon, when he was with his mother Amy at the Kalahari Resort in the Wisconsin Dells.

Earlier in the day, Amy had pulled Timothy out of school, and took him to the zoo and Key Lime Cove Resort in Gurnee, Ill., near the Wisconsin border.

"He said him and mom were on vacation," said James Pitzen, Timothy's father, to WBBM.

But later in the day, Amy committed suicide. She left behind a note saying that Timothy was fine, and in the care of unnamed people. Police say Amy's past included mental illness.

Her car has been located and the family says the fact that Timothy's car seat and backpack were not inside may be a positive sign that the boy is with somebody else, reports the station.

"I have a feeling that he's somewhere safe, that he has not been hurt or injured in any way, and that the people who have him don't know what's going on," James Pitzen told WBBM.

Timothy is described as 4-feet-2-inches tall and 70 pounds with brown hair and brown eyes. He was last seen wearing green shorts and a Spider-Man backpack.

Anyone with information is asked to call Aurora Police at 630-256-5500.