A high school girl repeatedly begged for mercy while she was being tortured by her companions who finally took her outside, forced her to strip and shot her in the back of the head so she couldn't tell authorities what happened, Allegheny County Police said Tuesday. Rodney Lee Burton, 21, of the 1500 block of Oak Street, North Braddock, and Brittany Williams, 19, of the 200 block of McCutcheon Lane, Penn Hills, were arrested on charges of criminal homicide for the shooting death early Sunday of Dana Marie Pliakas, 17, of Murrysville. Services are scheduled this afternoon for Pliakas, a...