Motions to Suppress Evidence Obtained Via Improper Grand Jury Subpoenas

Motions to Suppress Evidence Obtained Via Improper Grand Jury Subpoenas

Defendants can file a motion to suppress to prevent evidence obtained through an improper grand jury subpoena from being used against them. This is an important protection against prosecutorial overreach and abuse of the grand jury process.

Some key things to discuss in an article on this topic:

  • Explain what grand jury subpoenas are and how they are supposed to be used properly
  • Discuss precedents like United States v. Calandra that limit motions to suppress in the grand jury context
  • Analyze standards courts use to evaluate whether a grand jury subpoena was improper or abusive
  • Provide examples of cases where courts granted motions to suppress
  • Discuss the policy implications and debate around these motions – e.g. balancing defendants’ rights vs. grand jury independence

Grounds for Suppression Motions

Defendants can raise several arguments in suppression motions regarding improper grand jury subpoenas, including

  • The subpoena violates the Fourth Amendment’s particularity requirement or constitutes an unreasonable search/seizure
  • The subpoena exceeds the grand jury’s investigative authority
  • The prosecutor used the subpoena for an improper purpose, like intimidating a witness
  • The government failed to follow proper procedures for issuing or serving the subpoena

Courts scrutinize subpoenas to ensure they are not being misused “as a means of discovery in aid of [the prosecutor’s] case.”
However, defendants face a high burden in challenging subpoenas given the grand jury’s broad investigative powers.

Prosecutor’s Burden

If the defense shows a defect in the subpoena process, the burden shifts to the prosecutor to justify admission of the evidence.
The prosecutor may argue:

  • Any violation was merely a technical error that did not impact the defendant’s rights
  • The evidence would have been inevitably discovered through proper means
  • Exclusion would impose too high a societal cost

Prosecutors often prevail on these arguments given the preference for admitting relevant evidence. But clear constitutional violations or systemic abuse of grand jury process may warrant suppression.

Notable Examples

In United States v. Calandra, the Court refused to suppress a witness’ testimony despite an unlawful search to uncover his identity.
But where subpoenas directly violate privilege, like seeking defense strategy, suppression is more likely.
Courts have also suppressed bank records obtained by grand jury subpoenas that did not comply with Right to Financial Privacy Act procedures.
Overall, however, suppression remains the exception in federal courts due to preference for full admission whenever possible.


Motions to suppress grand jury evidence face an uphill battle but serve as an important check on government overreach. Defendants must strategically identify the most compelling grounds for suppression to have any chance of prevailing. Suppression of grand jury evidence remains rare, but may be justified in cases of egregious misconduct by prosecutors.


[1] United States v. Calandra
[2] Federal Criminal Lawyers – Motions to Suppress Federal Subpoena Evidence
[3] Challenging Federal Grand Jury Investigations