What happens in the other house is out of your hands. Pretty much the same thing for school. But you can control what goes on in your house. I suggest you get the book, "SOS Help for Parents," by Lynn Clark, and follow its guidelines.
Along with the house discipline you have to realize he has had some pretty tough times and is probably just in a survival mode. So give him lots of love and your time. Also do let the school know about his background and do ask them for help. Best wishes!
Sounds like a tough home situation for the guy. Have you talked to Child protective services about him and the family.
I agree. If that house is that bad, he shouldn't be going there at all. U should try to get full custody and if they want to see him, make it supervised and at ur house or a public place. Also get him some help. Take him to seee a therapist, it sounds like he needs more help then u can give alone. Another thing, u should hide or put up so he can't get all the sharp items. If u need it, take it out then as soon as ur done put it away. He sounds like he would be a great kid if he didn't have contact with his old home. Good luck.
Speak to the Childrens services he should not be in that home if thats the one that has treated him badly,no child should be locked into a room, poor boy he is acting out because of what has happened to him and he needs help, speak to your doctor,The boy will still need to know that there are boundaries and when he is bad to you a time out may help, so he knows he cannot behave like that ..Get some advice and counselling ...Good Luck I see you care about this child , so he has you, thats good .
I'd try to get full custody. The other home sounds like poison.