ALEX GORDON – I had done this a few dozen times myself, 6,000 miles away from my Alexandria, Va., apartment. As an Army infantryman in Iraq, Iâ€™d always been on the trigger side of the weapon. Now that I was on the barrel side, I recalled basic trainingâ€™s most important firearm rule: Aim only at something you intend to kill. I had conducted the same kind of raid on suspected bombmakers and high-value insurgents. But the Fairfax County officers in my apartment were aiming their weapons at a target whose rap sheet consisted only of parking tickets and an overdue library book.