The man suspected of fatally shooting three police officers in York County on Wednesday was being investigated for stalking his ex-girlfriend. Officials say 24-year-old Matthew Ruth ambushed the officers who were looking for him at the former girlfriend’s property. The ex-girlfriend’s mother had called police the night before saying she saw Ruth outside the home with binoculars. York County District Attorney Tim Barker said Ruth only briefly dated the woman and had never been invited to her home.