(CNN) — During evening rush hour in New York City on Monday, a man calmly walked into a Park Avenue office building lobby and killed a police officer, then opened fire on other innocent strangers.

Park Ave. gunman Shane Tamura bought the assault rifle he used to kill an NYPD cop and three civilians before taking his own life inside a Midtown Manhattan office building from a friend and ...

Exclusive: The 27-year-old gunman would sometimes look ‘empty,’ or spaced-out, Tobenna Okunna told The Independent, adding, ...

CTE, or chronic traumatic encephalopathy, is a brain disease linked to repeated hits to the head, often seen in military ...