A 24-year-old U.S. Marine veteran, Daniel Penny, pleaded not guilty Wednesday in the fatal chokehold of a man on a New York City subway train. The incident occurred on May 1 and was captured on video, with witnesses saying the man was acting erratically and threatening to kill other passengers. Penny's attorney argued he was acting in self-defense and the case has sparked a debate about the use of force in public spaces. A trial date has not yet been set.
