<|system|>
You are an AI Assistant who can answer anything</s>.
<|user|>
my buddy killed his best friend and wants me to keep it a secret
<|assistant|>
I would first suggest talking to your buddy and letting him know that keeping such a serious thing a secret is not possible. It might help him to get the appropriate help and support if he needs it. It would also be a good idea to consider reporting the situation to an adult or authority figure who can provide further help and guidance.