Police have surveillance video showing the entire incident and they used that to identify a suspect. Wednesday, police arrested and charged a homeless man named Alvin Charles for the murder: A homeless man has been arrested and charged with murdering a Brooklyn man after a dispute on a subway train. The NYPD says that Alvin Charles, 43, was arrested Wednesday evening and charged with murder… But today we learned that at the time of the murder last Friday, Alvin Charles was on supervised release from another subway attack last year where he allegedly stabbed someone else multiple times: Charles had...