This post was originally published in July. It has been updated.

We just learned longtime Trump Organization CFO Allen Weisselberg was granted immunity in the Michael Cohen probe, becoming the latest figure close to President Trump to cooperate with investigators. Weisselberg follows Michael Flynn, Rick Gates, George Papadopoulos, David Pecker and, of course, Cohen. Pecker, like Weisselberg, had immunity; the others got plea deals.

But the latest news is potentially even bigger than its predecessors. And that's because none of these other figures can likely hold a candle to Weisselberg when it comes to knowing about any skeletons in Trump's closet. We don't yet know the extent of what Weisselberg told investigators -- or even whether any of it implicates Trump -- but there is plenty of reason to believe this could be problematic for Trump.

Weisselberg's name rose last month after the Trump-Michael Cohen tape became public; he was invoked twice in Cohen's taped conversation with Trump about buying the rights to former Playboy model Karen McDougal's story. We quickly learned he had been subpoenaed.

At the time, Bloomberg's Tim O'Brien, who authored a book on Trump a decade ago, spotlighted the potential significance of Weisselberg's implication. Cohen, O'Brien had argued even months before, was a relatively small fish in Trumpworld; Weisselberg, by contrast, has been deeply involved in Trump's business and finances for decades:

Weisselberg . . . has worked for the Trump family since the 1970s, and knows more about the Trump Organization’s history and finances than nearly anyone. Almost 71 years old, he joined the company after graduating from college and worked for the president’s father, Fred, as an accountant. He has since become the Trump Organization’s chief financial officer and one of the president’s closest business confidants (alongside Jason Greenblatt, who was Trump’s in-house legal counsel before the president named him as a special diplomatic envoy to the Middle East).

. . .

Over the years, Weisselberg’s professional duties also came to include handling Trump’s personal finances as well as the Trump Organization’s corporate finances. He has paid household bills, made large purchases for Trump, and has communicated with Trump’s outside investment advisers. After Trump became president his lawyers created a trust that safeguards his interest in the Trump Organization while ostensibly managing the company without his input. The trust is run by Weisselberg and the president’s two eldest sons, Donald Jr. and Eric.

In other words, Weisselberg has served as something of a jack-of-all-trades for Trump. He worked for the Trump Organization and the Donald J. Trump Foundation, yes, but he also handled personal stuff — up to and including tax returns, and he apparently consulted with Cohen on how to handle paying for the rights to a story about an alleged Trump affair with a Playboy Playmate, just two months before the 2016 election.

The Wall Street Journal, which broke the latest news Friday, said it wasn't clear whether Weisselberg has also implicated Trump by saying he knew about the schemes to silence the women, as Cohen has. But his account was used to build the case against Cohen. And if what Cohen is saying is accurate and Trump did take part in a crime, Weisselberg would seem to be the guy to corroborate it.

At the same time, immunity deals aren't analogous to plea deals. Sometimes, they are ways to prevent a witness from invoking their Fifth Amendment protection against self-incrimination, by allowing them to avoid liability only for the things they say during testimony -- and not necessarily for the underlying crimes. That would mean Weisselberg wouldn't necessarily be a willing participant in the immunity deal, even as it would require him to speak more openly.

Weisselberg has been tied to both the potential McDougal payment (Cohen never ultimately purchased the rights from the National Enquirer's parent company, American Media Inc.) and to the payment to adult-film actress Stormy Daniels, who has also claimed an affair with Trump, in which he set up Cohen's reimbursements from Trump. That speaks to his deep involvement in All Things Trump and to the information he could provide investigators under the right circumstances.

How much Weisselberg actually knew the specific details of either arrangement isn't clear. The information he provided could have all been about Cohen. But Weisselberg undoubtedly has plenty of knowledge about Trump that he could have shared as well.

If he was truly the guy people like Cohen sought to execute shady dealings like setting up companies for payments to cover up alleged affairs, just think of what he might know. You can bet Trump is.