So I've distilled my comments down these comments and one question:
When agents/officers are the targets of investigation, they are the very often the first and foremost to "lawyer up", decline comment, cite "an ongoing investigation", etc...
I've never heard of any agent cooperating with an investigation against them. In fact, in the recent case of the Boy Scout being shot, the investigator was told he'd lose all friends in the bureau if he pursued the case.
My question to you is: If they won't cooperate, why should anyone else?
Allow me to make it short, simple and easy for you. From post #143:
A couple of agents want to check the serial number on your gun, let em.
Checkmate! End of arguing with HamiltonJay!