GPS System is Latest Target in Peterson Probe

The probe into the disappearance of Stacy Peterson appears to be focusing on obtaining physical evidence of a murder and on records from a GPS system in husband Drew Peterson's SUV, the Chicago Tribune reports. One new search warrant calls for the seizure of materials such as blood, fingernails or other material that could be DNA-tested.

The warrant also names "blue plastic, lead weights, plastic shavings, plastic scuff marks, circular impressions or carpet indentations," and other evidence related to the theory that Stacy Peterson's body was transported in a blue plastic barrel. Meanwhile, officials continue to search a canal near suburban Lockport, where the body might have been dumped, the Tribune reports. (More Stacy Peterson stories.)