<human>: Here's the story, my family has been looking for a Boxer for about 3 months.  We have previous Boxer-owning experience and know we love the breed.  After a few breed confusions and other issues, we found an 11month dog on CL.  We brought him home around 7pm on Sunday night.  The first thing he did was try and attack my Newfie through the fence.  After some careful introduction, he got over that, but still growled a couple of times.  I've had abused and mistreated dogs before, and been able to help them.  
So that first night he spent the whole time whining.  We learned: he isn't potty trained; he has no reaction to a name of any sort; absolutely none of the basic training.  He's not playful, he's scared, his first reaction is to flee, then to fight aggressively.  
The next morning, at around 6am, he broke out of the backyard while left to pee for 10 minutes.  Evidently he squatted around at neighborhood kid's houses until this afternoon.
He not happy.  No part of his personality is that of a Boxer.  His one shining, redeeming quality is that he LOVES kids.  He's great with them and sweet.  Still not playful, but he'll stick by their side contently.
Ultimately we think he was being used as a bait dog or originally hoped as a fighting dog.
My question is... should we try.  I keep seeing glimmers of a good dog, but he has NO training, he doesn't even recognize responding to the sound of a voice.  It will be an ass ton of work, but I want to give this boy a better life, but if it's a lost cause, I'd still like an actual Boxer.

Opinions, advice, ideas?  I'm really torn.  Either we commit to him, or we contact his previous owner (who will likely ignore me) then try to find him a new home with full disclosure.... HELP!

Can you give me the gist of the text in a nutshell?
<bot>: Got a Boxer off CraigsList, person lied or omitted (surprised?) now need to decide to keep him or not.