Amidst President Donald Trump’s ongoing threats to revoke security clearances from various critics, perhaps the most mysterious person on his enemy list is Bruce Ohr, the Justice Department lawyer who has repeatedly been a Trump target for reasons that have never been clearly articulated. Ohr has never criticized Trump as far as anyone is aware, and has worked at the Justice Department as an award-winning civil servant for nearly thirty years in Republican and Democratic administrations alike.

It has been noted that Ohr had ties to the notorious Christopher Steele dossier and that his wife worked for Fusion GPS, which hired Steele, a former British agent, to investigate Trump. But there is quite likely another reason which could trouble Trump even more: Ohr’s job in the Justice Department involved facing off against Russian crime boss Semion Mogilevich whose operatives have been using Trump branded properties to launder millions of dollars for more than three decades. If the FBI’s investigations turn toward Trump’s ties to Russian organized crime, which is entirely foreseeable, the president may be interested in trying to delegitimize those efforts as he has attempted with other aspects of special counsel Robert Mueller’s probe. What the public should also understand is how Mogilevich has served as an agent for Vladimir Putin’s efforts in the United States and abroad.

If one tracks Trump’s ties to Russia, the name Mogilevich pops up more than any single name, beginning in 1984 when alleged Mogilevich operative David Bogatin bought five condos in Trump Tower for $6 million in cash. Over the years, no fewer than 1,300 Trump-branded condos were sold in all cash purchases to anonymous shell companies—the two criteria that set off alarm bells among anti-money laundering authorities. In 2002, after Trump had gone belly up in Atlantic City, Bayrock, a real estate development company that allegedly had ties to Mogilevich, moved into Trump Tower and partnered with Trump—in the process bailing out the bankrupt real estate mogul and putting him in a position to eventually run for the presidency.

And Ohr is not the only Mogilevich specialist who has been the subject of Trump’s ire. Last September, former FBI lawyer Lisa Page was fired from her position on Mueller’s probe into the Trump-Russia scandal after anti-Trump text messages exchanged between her and Peter Strzok came to light. (Strzok, a member of Mueller’s team with whom Page was having a relationship, was also fired.) However, little attention was paid to what may well be the most interesting item on Page’s resume—her considerable experience prosecuting money laundering cases involving Russian organized crime, including working with the FBI’s task force in Budapest to prosecute a money-laundering case against Dmitry Firtash, the Ukrainian oligarch who partnered with both Paul Manafort and Semion Mogilevich.

“For him to be in the Justice Department, and to be doing what he did, that is a disgrace,” the President recently told reporters in reference to Ohr. Why go after Ohr, when many close observers assess that he was doing his duty by reporting Steele’s information to the FBI in late November 2017? Sitting on that information from the former British intelligence officer, who had his own track record helping the United States fight Russian organize crime, would have been a serious dereliction. And why does the president risk so much politically by even threatening to pull the security clearances of an active Justice Department official without any of the ordinary procedures for doing so?

In sum, a key to understanding Trump’s relationships with Russia goes through organized criminal syndicates. As I report on all this information and more in House of Trump, House of Putin, unlike the American Mafia, Russian mobsters operate as de facto state actors, with high-ranking crime bosses like Mogilevich working with and at the behest of Putin. All of which raises the question of whether Trump, by coming down on Ohr and perhaps also Page, is trying to keep the real story behind his many ties to Mogilevich operatives from unraveling.