The FBI and U.S. Marshal's Office are now helping police in the search for 6-year-old Timmothy Pitzen, who was last seen with his mother last week in the Wisconsin Dells.
Authorities say 43-year-old Amy Fry-Pitzen checked her son out of school and took him on an unannounced vacation.
She was found dead in a Rockford hotel room after apparently committing suicide.