During evening rush hour in New York City on Monday, a man calmly walked into a Park Avenue office building lobby and killed ...

Officer Didarul Islam, 36, who was guarding the building on a paid security job when he was killed, had served as a police ...

LAS VEGAS -- The gunman who killed four people before taking his own life in a midtown Manhattan office building that houses the NFL's headquarters had for years sought medical help for frequent, ...