Some of us have called this "Islamic terrorist related" from the first shot, mostly because this is exactly what they trained for, and videotaped, and promised to do.
Maybe each shooter was handed one single round of ammo. The missed shots would have surely been followed by another, if it had been available. What if all these shootings were just tests to pick the line-up for later exercises? Or tests of loyalty of some sort? Or simply tests for accuracy?
There are many possible explanations for "why didn't they shoot everybody?", but the fact remains that the Capitol region is experiencing some great degree of terror and its subsidiary effects.
It would also be reasonable to expect, now that so many assets are in the DC area, the same thing in other areas. Or something bigger.
We've seen those dogs bite. We've been told they're vicious. We've even seen it on tape, live from New York. Yet for some insane reason we're still reaching out saying "nice doggie, good doggie".