BOLINGBROOK, Illinois (CNN) -- Police are using tracking dogs, airplanes, infrared sensors and volunteers on foot Tuesday to look for a young mother who disappeared nine days ago, leaving her 4- and 2-year-old children behind. Stacy Peterson, 23, has been missing from her suburban Chicago home since October 28. 1 of 2 Friends and relatives of Stacy Peterson, 23, say her disappearance is suspicious. Her husband of four years, Bolingbrook police Sgt. Drew Peterson, 53, reportedly has told police his wife said she was leaving him for another man, and police are not treating the disappearance as a criminal investigation....