I believe that perhaps the best way to go at this is much the same way that classically the United States has worked to rout out mob families. You put pressure on the people that you have strong evidence against, get them to turn on their co-conspirators and get the inside information, and keep flipping the dominoes down the chain until all the truth comes out. This is being done in such a way that it's hard, unless you have inside information or there's a huge mistake like what I discovered. It's hard to get inside information into investigators' hands.
On June 7th, 2018. See this statement in context.