Congress has failed the American people on gun violence. Despite shootings in Lafayette, Chattanooga, Charleston, Newtown, Aurora and too many other cities across the country, Congress hasn’t passed any legislation to prevent future tragedies. In Boston, Everett and Cambridge, five people shot to death overnight last Wednesday evening. Last month, a young innocent mother of … Continue reading MetroWest Daily News Op-Ed: Markey: Gun violence is preventable, not preordained