I Have A Grandson Who Is Acting Out With Very

I have a grandson who is acting out with very bad behavior, wants to kill siblings, may try to molest them, we are at breaking point. This child is lying, stealing, pooping his pants, hurting his siblings, says voices tell him to do stuff. We have tried to get help and no one has really helped, even contacted dr phil and got no response. My daughter is now in process of leaving her husband and kids, she can no longer take it, The father is fed up to but doesn't know what to do with kid and I don't want the kid. If this kid does hurt his sis or brother, he won't get a chanceto hurt anyone else, I promise u. Can someone give me info on where I can get this child help, I really think he has a mental problem, there is so much more info I can tell u, he is obsessed with sex and more