There is a tiny link that's easy to miss in the USA Today story that links to the student's interview on CNN. The interview is well worth the watch, particularly where he's talking about using the stun gun. He clearly did not want to use it. Indiana mom sends son to school with stun gun to confront bullies - CNN.com
I am also wondering what law he violated, given that he was arrested. Are stun guns illegal in Indiana? It may have been against school policy for him to have the stun gun, but police have no authority to arrest someone for violations of school policy.