… Gregory Alfred, 25, was extradited back to New York after police picked him up at his mother’s Sayreville, NJ home over the weekend. […] While speaking with cops, Alfred explained that he set out to slash white people because he blamed them and “the system” for preventing him from freely smoking weed, police sources said. He allegedly targeted 53-year-old Poland native Janina Popko, cutting her across the neck as she was walking near the corner of Beverly and Rugby roads in Ditmas Park, Brooklyn on March 10, police sources said. …