I'm curious if the state has the equivalence of Florida's "Castle Doctrine". That would go a long way in helping the victim (homeowner). My problem with this is the criminal was shot in the back. Now that can be explained in a multitude of ways but still I'll be curious to watch this. I'm almost tempted to see if a copy of the complaint can be found online.
As an aside, handling criminal cases in Florida (lawyer), I had many a client want to sue the police or their intended victim. One special case wanted to sue the guy who broke his jaw with a baseball bat after he had broken in at four in the morning. Claimed he wasn't looking for a fight just some easy to take away valuables and the homeowner charged him all unreasonably screaming like a whacko (paraphrasing, had to remind myself I wasn't allowed to start laughing while he was telling me about how unfairly he was treated by the homeowner). Beat him a few times with the bat, got some nasty bruises and one of the hits connected with his jaw and he lost a few teeth, then he decided it was time to leave. The police had an entirely different version of course. Then I told him I'd take the case for a five thousand dollar up-front retainer, a thousand dollar a month minimum payment into the retainer each month, and would bill at two hundred an hour.
He flipped out, started screaming at me, and the jail guards got involved. Safe to say I didn't take the case. But a sucker is born every minute and the legal research I could have charged for to tell him he didn't have a chance would have been icing on the cake. Granted I knew he wouldn't have the money and I'd more or less told him earlier in the meeting that I thought any lawsuits he'd want to file would be a waste of time and money. I just wanted to see his reaction. I felt bad for his grandma, she was paying me but in the end she was the one who helped me convince him to take the deal. If he hadn't he would have been looking at some serious time.
So what does that have to do with this. This scum bag either filed suit Pro Se (himself without a lawyer), or found a lawyer who is willing to take his money or is a very conniving SOB who thinks the Home Owner or his insurance policy will want to settle quick and relatively cheap. A good solid personal injury defense can run you an easy fifty grand before it is all over and that's if you win. You lose, you pay a lot more.
Now unless the SOB and his client aren't willing to walk for ten grand I'd tell them to go pound sand and take it before a jury. Do an offer of judgment (every state is different) with the hope he'd get awarded nothing by the jury and seek attorneys fees (thinking Florida) from the Plaintiff after for not taking the deal.
There is a whole host of unanswered facts and questions, so no one can really say one way or the other, sadly. But I'd be curious what the complaint says.