The weapons that National Guard troops now carry in Washington, D.C.

WASHINGTON — The majority of the more than 2,300 National Guard troops deployed in Washington to support law enforcement began carrying weapons this weekend. But as in other such National Guard deployments, the troops have been told to use their M17 pistols and powerful M4 rifles only for self-defense or as a last resort, two Defense Department officials told NBC News. Under the rules of engagement, deadly force is authorized only “upon reasonable belief of an imminent threat of death or serious bodily harm,” one of the defense officials said. And a bad actor must have the “ability and opportunity” to put a guard member in jeopardy or inflict serious bodily harm. The focus for the guard members, the official ad