According to the OP, his dad is NOT mentally ill, demented or incompetent. If this is the case, then he’s not going to be “placed” anywhere. He will make his own choices. He may indeed have undiagnosed dementia or,alternatively, just be an abusive SOB. If the latter is the case, then it’s probably way past time to get mom out. She may not be willing to do this. Abused spouses don’t always choose to leave. Sounds like a mess. Still a good idea to get home health care and be sure his doctor knows what’s really going on.