For something like that there is likely a paper trail -- and a long one, and a clear one, including contracts in some cases. Indeed, we already have a lot of it on the public record. Not necessarily as proven evidence of illegal activities, but the surface deeds which the FBI and Special Counsel Mueller are most-certainly looking into. Keep in mind that we know that there was a long period where Trump had a very difficult time raising money and was in desperate need of funds, teetering on the edge of bankruptcy (again). U.S. banks wouldn't lend to him, and European banks wouldn't lend either. All reports have long been that the only place he could get money was from Russia.
So, that takes us to things like Trump buying property in Florida for $40 million and then selling it just a few months later to a Russian oligarch he never met for $100. Or the major story in the New Yorker magazine written brilliantly by Adam Davidson about a hotel Trump built in Azerbaijan which was in the middle of nowhere and was almost impossible to get to. The facility appears to have been financed with money from Iran's Revolutionary Guard, which is a terrorist organization, and done in conjunction with known-corrupt Azerbaijan officials, the Mammadov family, an apparent massive violation of the Foreign Corrupt Practices Act -- and all done with no vetting or due diligence. Even a Trump lawyer acknowledges the rampant corruption. (“I’m not going to sit here and defend the Mammadovs,” Alan Garten is quoted. But, from a legal standpoint, the lawyer argues, the Trump Organization was blameless -- something contradicted and explained in minute detail by the dean of George Washington University law school, who is an expert in the Foreign Corrupt Practices Act, which doesn't even require fore-knowledge, but just participation.) Further, an inside Trump executive is quoted in the article as saying that this was the way business was done at the Trump Organization. When asked if deals like this were at least unusual, the executive laughs. "“No deal there seems unusual, as long as a check is attached.” So, it seems the Trump company is littered with illegal deals like this.
It's a great article, riveting to read, filled with remarkable detail. (For instance, the Trump lawyer actually let author Davidson read the Mammadov contract.) You can check it out here.. But the important thing is, if a reporter from the New Yorker magazine can track down this one story...you absolutely KNOW that a) the FBI can too and will be following up on it, and b) the FBI can and will be following up on all the other rumored, corrupt deals the article references -- and can and will find more. They're the fricking FBI, after all (the official term). Not a guy writing an article and hoping for the best.
And all of these things are on the public record, as well as others reported in the news, like two, odd airport events when Trump's plane and one from a Russian oligarch happened to be landed on the tarmac at the same time, each occasion for less than two hours, in Charlotte, North Carolina, and Las Vegas.. Both apparently by pure chance. And maybe it was, both times. It's possible. Though the Russian's claimed "he was just there on business with someone else" has never been explained what that business was. Perhaps it was to talk about adoptions. Which brings me back to my original point --
I am sure the FBI and Mueller are investigating into Trump conspiracy with the Russian government, and may well be able to find vast proof of illegal acts -- but -- I believe that the way they are most likely to find evidence of illegal actions by Trump with Russia is through financial dealings. Not only do I believe that they exist, but that they have being going on for a great-many years.
Which brings us back to the admitted Russian money launderer, Irakly "Ike" Kaveladze, being the eighth person in that meeting with Don Trump Jr., Jerod Kusher -- one of Trump's top advisers and his son-in-law, and campaign head Paul Manafort.
I do not believe the story of this meeting ends well for Trump. And that's just the meeting.