The modern JFK conspiracy. Many people will believe it even though there is no real proof. Take the grassy knoll. There are different well known interpretations on methods for figuring out the most likely truth but all come down to eliminating all assumptions in data gathering. The other car? First you have to prove the particular car was there and it acted in a certain way. Video or the like. If so, that can be proven. However the assumption is that it was never found therefore it must have served some deliberate and nefarious purpose and somewhere disassembled. Or simply dropped in a lake. Like JFK, where you cannot include anything about the grassy knoll because there is no proof anyone was there performing some act as a co-conspirator. Certainly not someone there with a rifle.
It will eventually be like Trump. Whatever the investigators come up with, connecting the dots will be seriously scrutinized. Do any of those dots or connections contain any assumptions. And if so, are any used in coming to a conclusion. It was also like Bill. After a huge investigation they couldnt connect the dots in what they were looking for. The investigators did their jobs in not factoring in assumptions. So they nabbed him on lying about a blowjob by an intern more than happy to do it. Regardless, millions of people include assumptions because they want to believe.