That's a situation that is never easy. Jane is right though. Inform Social Services. You may feel that you are passing the buck but your not. You are not responsible for the behavior of others but you are responsible "morally" or "professionally" to report or point it out to the appropriate person or persons. I don't know in your State, but leaving the scene or not helping in a scene of an accident you can be help accountable. But I get a feeling Susan that you know all this as you are a smart lady from threads I've read of yours. However exploring different point of views hopefully will give you something that will help.
All the very best.
Beer (adrien)