McCowan's son, Dustin McCowan, was charged with Bach's murder last month after the young Portage woman went missing and was later found dead along some railroad tracks.
The Porter County Sheriff's Department made it clear, though, the elder McCowan, a Crown Point police officer, is not a person of interest at this time. The cell phone warrants are part of the investigation, said Cpl. Larry LaFlower in a statement to the Sun-Times.
Police want to check which cell tower Bach's phone connected to before her body was found. Police will check call records, voicemail, text and data from Aug. 15 through Sept. 20.
Joseph McCowan's phone will be checked for calls, text and data from Sept. 2 to Sept. 20.