Harvard Law School professor Alan Dershowitz said Monday the charges being filed against former Trump campaign chairman Paul Manafort and his former business partner have nothing to do with President Trump's campaign or colluding with Russia.

Instead, Dershowitz said prosecutors likely want to use anything in Manafort's past to get him to spill the beans on any wrongdoings he witnessed during the 2016 presidential election.

"It's all about leverage. They're going after Manafort on something that apparently has nothing to do with Trump — years ago, his own business," Dershowitz told Fox News Monday morning, shortly after Manafort was photographed turning himself into the police.

"But what they're saying to him is 'we gotcha now, and we don't care about that, but if you can tell us something about Trump and the campaign and collusion, we'll give you a get out of jail card free,'" Dershowitz added. "So it's all about leverage. That's the way prosecutors work."

Dershowitz said special counsel Robert Mueller wants to see how the "first domino" falls and if it leads to a second and third domino collapse that paves the way to Trump himself.

"If he has nothing to offer, he's just going to have to defend himself on these financial charges that have nothing to do with Trump. This shows the danger," he added. "Sometimes prosecutors can twist you not only into singing but into composing, into making something up against somebody. They're so desperate to make a deal. ... If you can get yourself out of trouble by turning somebody else in, a lawyer is going to help you try to do that."

Manafort and business partner Rick Gates were told to turn themselves in early Monday. They are expected to meet with the judge Monday and will likely make bail to avoid sitting in jail.

Dershowitz believes there is a "grand strategy" to Mueller's operation.

"If he only gets Manafort, at least he has earned some of his money — the special prosecutor. And if he can turn it into somebody a little higher and a little higher and a little higher, the dominoes begin to fall. So it's a win-win strategy for prosecutors and, of course, it creates vulnerability for the target," he added.