***The Shadow knows… and slays with a chainsaw!*** Someone is murdering women at a Boston campus with a chainsaw and acquiring body parts for some unknown purpose. Christopher George plays the lieutenant in charge of the investigation while Lynda Day George is on hand as a tennis instructor. “Pieces” (1982) borrows components of previous slashers, like “Psycho” (1960), “The Texas Chainsaw Massacre” (1974) and the first two “Friday the 13th” movies (1980-1981), but places the story at a Massachusetts university. Yet this is actually a Euro-horror flick shot in Madrid with some exteriors from…