The walls appear to be closing in on Donald Trump’s money man, Allen Weisselberg. According to the New York Times, “The Manhattan district attorney’s office appears to have entered the final stages of a criminal tax investigation” into the longtime chief financial officer of the Trump Organization. Charges could apparently come as early as this summer.

In recent weeks, a grand jury has been hearing evidence about Mr. Weisselberg, who is facing intense scrutiny from prosecutors as they seek his cooperation with a broader investigation into Mr. Trump and the Trump Organization, the people with knowledge of the matter said. The prosecutors have obtained Mr. Weisselberg’s personal tax returns, the people said, providing the fullest picture yet of his finances.

But is Weisselberg the big fish, or are prosecutors hoping to flip the longtime Trump loyalist? The New Yorker quoted a source as saying, “Allen is the one guy who knows everything.”

Weisselberg’s former daughter-in-law, Jennifer Weisselberg, says she has talked to investigators several times and has turned out multiple documents. She is among those who think her former father-in-law will turn on Trump. The New York Times adds:

The investigation into Mr. Weisselberg focuses partly on whether he failed to pay taxes on valuable benefits that Mr. Trump provided him and his family over the years, including apartments and leased cars as well as tens of thousands of dollars in private school tuition for at least one of his grandchildren. In general, those types of benefits are taxable, although there are some exceptions, and the rules can be murky.

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