I am so sorry you and your family is being put through this. You sound as though you have your priorities in the right place, with the children. They are innocent victims in a case like this so please do your best to protect them.
If he was working somewhere else, he would have been fired...IMMEDIATELY! Is there some skill he has that makes him the only person qualified to do the job? It sure sounds like he should be let go. Protecting your business is also going to protect your children.