From Slate here:
Felix Sater was born in Russia and moved to the United States with his family when he was 8. His father Mikhail has connections to Russian organized crime and was once convicted of extortion. The younger Sater ended up working at a company called Bayrock, which had offices in Trump Tower and, beginning in 2002, partnered with Donald Trump on several development projects. Bayrock’s role in the projects involved soliciting outside investors.
It would be naive to think that Trump has not rubbed elbows with a lot of unsavory people, organized crime figures among them.
So either law enforcement doesn’t really care about these mob connections or they’ve been told to stay away by Trump honchos.
But there’s always the press, and if it turns out that Donald Trump is nothing more than a garden variety criminal well, that mud should be tossed at him and he should be held accountable for what he’s done just like everybody else.