The Reason There Is So Much Evidence On Manafort And Trump Is...

[lame54]

They've always operated in the white collar world where no one(or rarely) ever gets in trouble
No need to work very hard in hiding the evidence

[The Velveteen Ocelot]

1. It's also because in the white-collar world there is always a paper trail

no matter how hard you try to disguise your transactions, but the paper trial can be very hard to follow because it leads through all kinds of shell corporations, sham deals, and in this case international entities, and it takes a very major investigation by multiple experts (forensic accountants and the like) in order to follow the money. So they often do get away with it.