This happened in my state, and according to what I heard on the local news, the prosecuter is planning to file charges against the three oldest in juvenile court as "unruly children", since that's the only charge he can legally bring against them. While the children didn't intend to kill the teacher, the nine year old girl that organized this wanted the teacher to be tortured.
Here's the Atlanta Journal-Constitution story about it:
http://www.ajc.com/metro/content/met...ge_tab_newstab