Guy brandished a firearm at a security checkpoint, refused to drop it, and was shot.
Good procedure and shoot.
zero was not present, but Joe Biden was.
There is some talk that shortly after the incident, someone unloaded a double barrel off the back porch, but they are keeping a tight lid on that one. (Go ahead, Snopes it)
http://www.foxnews.com/politics/2016/05/20/white-house-lawn-cleared-amid-report-shooting.html