What do I do

My step son who is 11 has a hearing at school next week for recommendations for expulsion. He repeatedly googles disturbing things such as school shooters, death, how to make pipe bombs etc. he claims he is being bullied but refuses to tell the teacher. He told me "I need to handle it myself". I am so disturbed by this his mother and my fiancé has put him in counseling etc and they claim nothing is wrong with him. My fiancé refuses to punish this kid for anything he does. I can not handle this anymore and I am almost ready to leave my fiancé completely because of his lack of parenting.. what would you do in this situation?