More than 100 times in 2 1/2 years, former U.S. House Speaker Dennis Hastert withdrew cash from his bank accounts to pay down a $3.5 million hush-money bargain, federal prosecutors say.

They don’t say why.

The formal charges against the affable Illinois Republican are as baffling as they are astonishing. Thursday’s indictment includes one count each of illegally structuring cash withdrawals and lying to the FBI about it. Each carries a possible penalty of five years in prison and a $250,000 fine.

This isn’t just yet another Illinois politician winding up in the crosshairs of federal prosecutors. The underlying narrative leaves much to the imagination. The bottom line is that Hastert allegedly agreed in 2010 to pay $3.5 million to an unnamed person to “compensate for and conceal his prior misconduct against Individual A.”

Details of the “prior misconduct” aren’t spelled out in the indictment. The criminal wrongdoing charged by prosecutors is limited to Hastert’s alleged attempts to conceal the payments.

According to an affidavit, he’d made 15 withdrawals of $50,000 each by July 2012 when bank officials - who are required to report transactions greater than $10,000 - questioned him. After that, he made frequent withdrawals of less than $10,000 “to evade the reporting requirements,” it says.

When FBI agents confronted him about the withdrawals, Hastert said he was stashing the cash because he didn’t trust the banking system, according to the feds. By that time, he’d withdrawn $1.7 million.

Why? The affidavit provides few clues. “Individual A” is a resident of Yorkville, where Hastert taught high school and coached wrestling from 1965 to 1981. The two have known each other “for most of Individual A’s life.”

Hastert left teaching for a seat in the Illinois General Assembly and quietly worked his way up to the U.S. House of Representatives, where he became the longest serving Republican speaker in history. He’s been a lobbyist since he left office.

Many of the people who knew and liked Hastert were, frankly, surprised that he rose to such national prominence.

But not nearly as surprised, no shocked, no stunned, as they are today.

On paper, he’s accused of moving money around illegally and fibbing to the feds about it. Between the lines, prosecutors suggest he has harbored a dark secret.

— Chicago Tribune