Not only do they not want anyone to know about the role they played in the assassination attempt, but they also don’t want people to know that they likely haven’t conducted any kind of investigation into it yet, and whatever paperwork that does exist on it is slim to none...at least the paperwork they haven’t deliberately destroyed or misfiled. Stall, deny, lie, obfuscate as long as you can to keep your criminality from being confirmed.
The FBI is investigating whether or not they covered their tracks sufficient to not be charged as criminal traitors deserving of death.