@501bob,
Please speak to your/his social worker before you give up on him. He's
17 years old, all right, but he's had much to deal with including the death of
his mother. He probably doesn't know how to channel his anger and needs
reinforcement and help in how to deal with set backs in life. The scars from
physical abuse will be with him for the rest of his life and he needs you to teach
him how to cope and how to receive, accept and give love. If you give up on
him now, you just reassure his original way of thinking. I know it's hard, but
please don't give up on him - seek help through social services and support
groups for foster parents. Help is out there!