"48 Hours" investigates "Mystery on County Road M"

Todd Kendhammer was convicted of his wife's murder in 2017. He claims he's innocent, and says she died when a pipe flew off a truck and hit the windshield on a Wisconsin road. Now his new legal team says there's powerful evidence the jury never saw. "48 Hours" correspondent Erin Moriarty joins "CBS Mornings" with a preview of her report, "Mystery on County Road M".