Demonstrators marched on Staten Island against overly aggressive policing after the death of Eric Garner. Mr. Garner, 43, died after being placed in a chokehold while the police attempted to arrest him for allegedly selling cigarettes illegally on July 17. His family and others have called for prosecutors to take action against the officer involved. The demonstration was also in the wake of Ferguson, Mo., where Michael Brown, 18, was shot and killed by a police officer.