It seems that a defense contractor who was allowed onto a Naval yard in Washington, D.C. decided to kill nearly a dozen people.
This nation was baptized in violence and can only be maintained through violence. This is what happens when you create a system that makes it acceptable to use violence to enact political change. Until the USA acknowledges its paternity, people will continue running around after incidents like this wondering where all of this violence is coming from. That's my opinion, at least.