As they build their two criminal cases against Hunter Biden, prosecutors are leaning hard on a surprising voice: Hunter Biden’s.

In several recent court filings, special counsel David Weiss extensively cited the president’s son’s 2021 memoir, "Beautiful Things," as evidence that he claimed improper tax write-offs and that he was using drugs when he bought a gun.

And Weiss’ team pointed to Biden’s openness about his drug use as giving prosecutors extra reason to bring criminal charges — even suggesting his memoir was a game-changer in their decision to prosecute him.

“The defendant’s choice to sell a book containing these admissions not only made the government’s case against him stronger, but also increased a potential prosecution’s general deterrence value,” they wrote.

Prosecutors amped up their use of the book in a series of filings this month responding to pre-trial motions from Biden’s lawyers.

Those motions underscore the reality that Biden’s criminal defense is scarcely contesting the facts as alleged by prosecutors; instead, it relies on purely legal arguments. And the prosecution’s response highlights a unique vulnerability faced by criminal defendants with public platforms.

“That’s the challenge for high-profile and political figures: They’re constantly saying things,” said William & Mary Law School professor Jeffrey Bellin. “And the more you say, the more evidence you create for the other........

© Politico