NEW YORK, July 30 -- A man stalked through a Manhattan office tower firing a rifle Monday, killing four people, including a New York City police officer, and wounding a fifth before taking his own life, officials said. The shooting took place at a skyscraper that is home to the headquarters of both the NFL and Blackstone, one of the world's largest investment firms, as well as other tenants. The gunman, identified by authorities as Shane Tamura of Las Vegas, had a 'documented mental health history, officials said. P10...