Grand Jury Subpoenas vs Trial Subpoenas: Key Differences

Grand Jury Subpoenas vs Trial Subpoenas: Key Differences

Grand jury subpoenas and trial subpoenas are two types of subpoenas used in the legal system, but they serve different purposes and have some key differences.

What is a Grand Jury Subpoena?

A grand jury subpoena is issued by a federal grand jury during a criminal investigation. The grand jury uses subpoenas to gather evidence and determine if there is probable cause to indict a suspect[1].

There are two main types of grand jury subpoenas:

  • Subpoena ad testificandum – requires someone to testify before the grand jury
  • Subpoena duces tecum – requires the production of documents or records

Grand jury subpoenas are broad in scope – they can request testimony on any matter relevant to the investigation. There is no requirement to show probable cause. The prosecutor issues grand jury subpoenas without judicial oversight[2].

Once served, compliance is mandatory. However, grounds may exist to challenge the subpoena, such as privilege, undue burden, or improper service[3].

What is a Trial Subpoena?

A trial subpoena is used during litigation to compel witness testimony or document production. Trial subpoenas are issued by the court or attorneys involved in the case[4].

There are also two main types of trial subpoenas:

  • Subpoena ad testificandum – secures witness testimony at a trial, hearing or deposition
  • Subpoena duces tecum – compels document or record production

Trial subpoenas are more limited in scope than grand jury subpoenas. They can only request evidence relevant to the specific case issues[4]. Parties must also follow discovery rules and protocols.

Key Differences

There are some important differences between grand jury and trial subpoenas:

  • Purpose – Grand jury subpoenas are investigative tools while trial subpoenas are used for litigation.
  • Scope – Grand jury subpoenas have a broader scope and parties can’t object on relevance grounds. Trial subpoenas are narrower.
  • Issuing Authority – Prosecutors issue grand jury subpoenas while courts or litigants issue trial subpoenas[5].
  • Challenging – It’s harder to quash a grand jury subpoena. Parties have more grounds to challenge trial subpoenas.
  • Secrecy – Grand jury proceedings are secret so subpoena details may not be disclosed. Trial subpoenas are public.
  • Service – Grand jury subpoenas only need to be served on the recipient. Trial subpoenas require service on all parties.
  • Compliance – Failing to comply with a grand jury subpoena can result in contempt. Non-compliance with a trial subpoena may lead to sanctions.
  • Records – Documents produced under a grand jury subpoena remain secret. Trial subpoenaed records enter the public court record.

Practical Implications

The differences between grand jury and trial subpoenas have important practical implications:

  • Recipients of grand jury subpoenas have less ability to challenge them and must comply or risk contempt charges.
  • Parties served with trial subpoenas can raise objections and work to limit scope through the discovery process.
  • Witnesses who testify before a grand jury may not disclose details while trial testimony is public.
  • Entities responding to grand jury subpoenas must take care not to waive privilege and maintain confidentiality.
  • Attorneys dealing with trial subpoenas should follow rules of service and court protocols.


While grand jury and trial subpoenas compel evidence production, they serve distinct legal functions. Understanding the key differences in scope, secrecy, service requirements and compliance is important for anyone involved in the legal process. Parties served with subpoenas should consult counsel to ensure they respond appropriately and protect their rights.