A New York City social justice activist was stabbed to death in front of his girlfriend as the pair made their way home from a wedding in Long Island on Monday. The shocking video shows a deranged man appearing on the street as he followed the pair before slaughtering the activist and fleeing the scene. The disturbing surveillance footage has provided police with a clear image of the suspect, who remains at large. (WARNING: The following footage some may find upsetting) VIDEO AT LINK............ As the New York Daily News reported, “The footage shows Ryan Carson, 32, and his girlfriend...