The gunman who allegedly shot and killed a New York City police officer has been charged with murder, officials said. Tyrone Howard, 30, of East Harlem, who has prior gang-related offenses, was also charged with robbery in the shooting death of Officer Randolph Holder and stealing a bike in the process, officials said. Holder and other officers were responding to reports of gunshots in East Harlem, which police sources said was connected to gang activity.