I have read the weapons laws for DC and have ruled out most of my usual defensive weapons. I do have my SureFire E2D that an have have no problemas carrying on commercial flights even before the newer lax laws. but DC is a big unknows and I have to traven there for work this sunday, would I be fairly safe with that "tool" ?
I think you'd be fine with it. There are no cutting edges or stabbing points (although a jab from one of those would leave some nasty but shallow holes).
It'd be a stretch to call it a weapon.
You might ask this is GD or the legal discussion forums. Perhaps even tactics and training would have some good answers/suggestions.