Sounds like trespassing? Check the rules in your state. I tried to look for it and came up with California and Georgia but no NC. It's there just have to look for it.
Consulting with a lawyer will immediately give you your options. army judge is right, those who tend not to carry insurance tend not to have assets for the lawyer to chase. But you never know. Also might want to see if there are any other sources for liability. The car didn't have insurance, did...
Copyrights are automatically created when you create the work. I would read the Copyright office page, it has a lot of great information.
I can't link it yet but it's copyright dot gov
Registering copyrights has several benefits, but it isn't 100% necessary. Read the site to get more...
What happened to the previous lawyer? Did he not have any succession plans or partners? You have set up a serious estate/asset protection plan. You are not going to be able to figure this out on your own, and putting protections, if any, at risk. You seriously need to contact an attorney well...
Did you have insurance?
Did you have insurance? They should take care of this for you. Call them up, have the other family contact your insurance company.
If there are injuries, and you are at fault, there is a possibility the other family may get a settlement, but again, you shouldn't have...