A former prosecutor has a stark warning for Jack Smith as he pushes furiously to convict Donald Trump before the presidential election.

The judge in Smith's classified documents case, Aileen Cannon, could block him from using certain evidence that was obtained by a grand jury in Washington D.C, according to former prosecutor Bill Shipley.  

Smith faces major roadblock

Smith pursued a grand jury investigation initially in D.C. before filing the charges in Miami. The grand jury files were transferred to Florida this week.

Trump's attorney, Evan Corcoran, was compelled to testify to the D.C. grand jury last March under the "crime-fraud exception" to attorney-client privilege.

Cannon isn't bound by the rulings of the D.C. court, Shipley said, presenting a risky situation for Smith. For example, Cannon could throw out Corcoran's testimony if she finds it violated attorney-client privilege.

"She can exclude Corcoran as a witness by upholding the claim of privilege. She can preclude SCO Smith from using any evidence she deems was obtained in an improper manner. That's the risk that Smith ran by conducting the case in the fashion he did," Shipley wrote on X.

Smith says that Trump misled federal investigators and his own lawyers about classified documents that were stored in his home.

Corcoran wrote a June 2022 letter to investigators stating there had been a "diligent search" of Mar-A-Lago months before it was raided by the FBI.

Trial faces delays

Any moves by Cannon to slow down Smith's prosecution are sure to bring backlash.

The judge has made clear she has no intention to rush through such a complex case, leading liberal legal experts to charge that she is trying to help Trump avoid accountability. Trump's valet and property manager have also been charged.

It's still unclear if Trump will ever go to trial in Miami, with an original May trial date scuttled.

Trump has argued he is the target of selective prosecution, pointing to Special Counsel Robert Hur's report on Biden's mishandling of classified information, which found Biden "willfully retained" top secret information as a private citizen. Democrats have insisted the cases are nothing alike.

Of the four criminal cases Trump faces, the classified documents trial likely has the best chance of an impartial jury.

Trump's other cases are in Atlanta, Washington D.C., and New York, all deeply liberal jurisdictions.

Smith is also prosecuting Trump over January 6th in D.C., but the Supreme Court's decision to consider Trump's immunity defense could push the trial past the election.