Nicely put Villan - the most level-headed and useful post in this thread so far. Heed Villan's words Dianavan, exclusion, litigation and navel-contemplation won't solve the problem. Sounds like you're in need of a proper structure being established by your school/education authority to enable this child to be taught successfully and safely (for both of you). Good luck.

Johnny :0)
(not a teacher, but an ex-youth worker who's had to deal with many teenagers' violent episodes)