15 Sep 23

Motions to Suppress Evidence Obtained Through Improper Federal Subpoenas

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Last Updated on: 16th September 2023, 03:21 pm

Motions to Suppress Evidence Obtained Through Improper Federal Subpoenas

When the government obtains evidence through improper means, the defendant in a criminal case can file a motion to suppress that evidence. This prevents the government from using illegally obtained evidence against the defendant at trial. One common situation where suppression motions arise is when the government uses flawed or improper subpoenas to get evidence.

Subpoenas are powerful investigative tools that allow the government to compel witnesses to provide documents or testimony. However, subpoenas must follow strict rules. If the government fails to adhere to subpoena requirements under the Federal Rules of Criminal Procedure, any evidence gathered may be suppressed.

What is a Motion to Suppress?

A motion to suppress aims to exclude evidence from being used at trial (see motion to suppress[1]). It asserts that the evidence was gathered improperly or illegally by investigators. If the judge agrees, they will suppress the evidence so it cannot be used against the defendant.

Suppression motions are based on the exclusionary rule. This rule excludes evidence obtained through unconstitutional searches or seizures (see exclusionary rule[1]). The purpose is to deter police misconduct and protect citizens’ Fourth Amendment rights.

In federal court, suppression motions are governed by Rule 41(h) of the Federal Rules of Criminal Procedure. Defendants commonly seek to suppress evidence obtained through:

  • Unlawful searches and seizures
  • Coerced confessions
  • Flawed eyewitness identifications
  • Wiretaps without probable cause
  • Defective warrants
  • Improper subpoenas

If the defense shows the government violated constitutional requirements, the burden shifts to the prosecution. They must prove that an exception to the exclusionary rule applies.

Requirements for Federal Subpoenas

Federal subpoenas must adhere to Rule 17 of the Federal Rules of Criminal Procedure (see Rule 17[2]). Key requirements include:

  • Subpoenas must state the court, title of proceeding, and command for testimony or document production.
  • Parties must request blank subpoenas from the court clerk.
  • Subpoenas should only compel relevant information.
  • Subpoenas must be served personally on the witness.
  • Witnesses can file motions to quash or modify unreasonable or oppressive subpoenas.

If agents fail to properly serve subpoenas or request irrelevant materials, the subpoenas may be improper. Defendants can argue this evidence should be suppressed under the exclusionary rule.

Common Bases for Suppressing Federal Subpoenas

Defense attorneys frequently file suppression motions alleging procedural defects with federal subpoenas. Common arguments include:

Subpoenas Violate the Fourth Amendment

The Fourth Amendment prohibits unreasonable searches and seizures. It requires probable cause for warrants. Subpoenas compel witnesses to turn over documents and testify. So courts analyze them under the Fourth Amendment reasonableness standard (see Fourth Amendment[3]).

If a subpoena requests broad categories of irrelevant documents, it may constitute an unreasonable “fishing expedition.” Other grounds for suppression based on the Fourth Amendment include:

  • Subpoena lacks probable cause
  • Subpoena is overbroad or vague
  • Materials requested are not relevant to the investigation
  • Subpoena imposes undue burden on witness

Subpoena Procedures Were Not Followed

Agents must adhere to subpoena requirements under Rule 17. Failing to do so can justify suppression. Examples of procedural defects include:

  • Not obtaining blank subpoena from court clerk
  • Failing to personally serve subpoena on witness
  • Not giving reasonable notice to comply
  • Exceeding scope authorized by court

Subpoena Violates Statutory Privacy Protections

Statutes like the Right to Financial Privacy Act limit subpoena access to personal banking records. If agents don’t follow proper procedures, the court may suppress the records (see 12 USC § 3401[4]).

Subpoena Used for Improper Purpose

Courts will scrutinize subpoenas for bad faith or improper motives. For example, a prosecutor cannot use a subpoena solely to pressure a defense witness not to testify (see JM 9-11.233[5]).

How to File a Motion to Suppress

Defense attorneys should file suppression motions pre-trial to exclude evidence early. The process generally includes:

  1. Filing a written motion stating the evidence to be suppressed and legal bases.
  2. Prosecution files a response.
  3. Holding a suppression hearing where both sides present arguments.
  4. Judge decides whether the evidence is admissible.

At the hearing, the defense must establish a constitutional or procedural violation. If they do, the burden shifts to the prosecution to justify why suppression is not warranted.

Prosecution’s Burden to Justify Admission

If the defense establishes a defect in the subpoena process, the burden shifts to the prosecution. They must convince the judge to admit the evidence anyway. Possible arguments include:

  • The violation was a technical error that did not impact the defendant’s rights
  • Excluding evidence would impair the truth-seeking process
  • Police acted in good faith when issuing the subpoena
  • The evidence would have been inevitably discovered through proper means

However, if the constitutional violation was egregious, the exclusionary rule strongly favors suppression. Examples of misconduct outweighing admission include:

  • Racial profiling in issuing subpoenas
  • Intentionally violating the defendant’s privacy rights
  • Recklessly misleading the court to obtain subpoenas
  • Using false information to get an overbroad subpoena

Appealing Denied Suppression Motions

If the trial judge admits the challenged evidence, the defense can appeal after conviction. Appellate courts review denials of suppression de novo. So they take a fresh look at whether exclusion is required.

For appeals, the defense must have properly preserved the suppression issue. This requires making timely objections and offers of proof at trial. The trial record must show how admitting the evidence harmed the defendant.

Common appellate arguments regarding improper subpoenas include:

  • The subpoena violated the Fourth Amendment’s particularity requirement
  • The trial judge failed to adequately scrutinize the subpoena
  • The prosecutor did not meet their burden to justify admission

If the appellate court finds the trial judge erred in admitting evidence, it will reverse the conviction. But prosecutors can sometimes retry the defendant without the suppressed evidence.


Motions to suppress are critical tools for keeping the government in check. When agents misuse subpoenas to improperly collect evidence, suppression provides a remedy. For the defense, winning a suppression motion can weaken or even destroy the prosecution’s case. Understanding the requirements for federal subpoenas and bases for suppression is key to protecting defendants’ constitutional rights.