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 suspected of targeting the National Football League headquarters in New York, killing four, was a former football player at two Southern California high schools.

Cops identified a man who sold the weapon to mass shooter Shane Tamura as his former supervisor in the Las Vegas area.