Here's another wrinkle, just to make things worse and more complicated.
Whatnext, you now have to do something immediately about this dog. Another poster earlier in the thread pointed out the folks who went to prison because their dog killed the woman in the apartment hallway.
From a legal standpoint "every dog is entitled to his first bite." That's because the owner has to be on notice that his dog is inclined to bite before he's liable.
But with this post and this thread, you've made it quite public that you know this dog is a problem. That's your notice, and it's a matter of public record. If your dog bites somebody now, you're completely responsible and may be liable in punitive damages. And your homeowner's insurance may not cover it, depending on the exclusionary language in your policy.
So you need to make a decision today about what you're going to do, don't put it off. Take the dog for a consult with the best trainer you can find (HOTD's Dog God sounds like a good one and not too far away), return it to the breeder, or have it put down.
But do it NOW.
Thirds!
I don't think my Dog God would mind the publicity of posting his website. (I'd be so embarrassed if he ever knew I said that, but it's true)
His Schutzhund dogs have fabulous drive and focus, and there are many videos segments and pics that show them working there. I am lucky to have been able to learn from him when he was still doing basic obedience classes on the side.
http://www.kraftwerkk9.com/index.php