Here, here! This is one point where I think I disagree with Ayoob. (It's just a personal preference, as he knows worlds more than I do about law and self defense.) It worked for me NOT to warn the perp. He ended up in cuffs.

We on this board make these assumptions that the perp will behave like a "good little burglar", or that he's not coming in with four of his armed friends. Do you really want to yell out to four drug-hyped nuts that you have a gun and you're right down the hallway? They may not behave rationally. Do you want to try to gun down five armed assailants? You've got more balls than me.