Shane Devon Tamura, the man identified as the gunman who killed four people in a deadly shooting at a midtown Manhattan office building that houses the NFL 's headquarters, was once a standout high school football player.

The gunman, who said in a note he believed he had CTE, targeted skyscraper that houses the NFL's headquarters.

Shane Devon Tamura was the 27-year-old man living in Las Vegas who fatally shot at least four people in a mass shooting at 345 Park Avenue in New York City on July 28. Here's what to know about the N.