Maybe I've seen too many movies but in investigations like these, why aren't people subjected to lie detector tests? Strap them in and ask a few simple questions.. Is there some law against it or are they not reliable enough to produce a valid result?
They could do it with Trump and broadcast it on some pay-per-view channel, pretty sure the whole world would tune in and then they could use the money to fund a new health care system. Win-win.
They can be duped. In fact members of the intelligence service are trained to trick them.