In the words of Yackoff Smirnoff, "... a warning shot is when they shoot your friend."
Seriously -
In this situation I sit like a mother bird on her nest, I cover and conceal my family and wait. I say nothing and do nothing until LE arrive and clear. However, at first sight of human flesh, or whatever is covering it, I announce, confirm (remember that good guys are assumed to be on way, and the fact that it isn't drunk brother hasn't been confirmed yet) and fire!