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Posted by Karren Kenney | Jul 29, 2025
When most people hear the words grand jury, they immediately think of high-profile criminal investigations or dramatic courtroom scenes on TV. In reality, federal grand jury proceedings are one of the most secretive and powerful tools in the United States justice system. They play a pivotal role in determining whether the federal government has enough evidence to bring formal charges against someone for a serious crime.
Whether you're a legal professional, someone involved in a federal investigation, or just curious about how the federal criminal system works, understanding how a federal grand jury operates is essential. This blog breaks down the process, participants, and implications of federal grand jury proceedings.
A federal grand jury is a group of citizens, typically 16 to 23 people, selected to examine evidence presented by federal prosecutors. Unlike a trial jury (also called a “petit jury”) that determines guilt or innocence, a grand jury decides whether there is probable cause to believe a crime has been committed and whether charges should be filed—this is known as issuing an indictment.
Federal grand juries are authorized under Rule 6 of the Federal Rules of Criminal Procedure and are convened to investigate possible violations of federal law.
The main function of a federal grand jury is to act as a buffer between the federal government and its citizens. Before a prosecutor can formally charge someone with a felony offense, they must first convince a grand jury that the evidence supports such action.
The grand jury process ensures that citizens—not prosecutors—ultimately decide whether there's enough evidence to justify putting someone on trial. This process helps guard against unfounded or politically motivated prosecutions.
One of the defining features of grand jury proceedings is their secrecy. The idea is to protect the reputations of individuals who may never be charged, encourage honest testimony from witnesses, and prevent those under investigation from fleeing or tampering with evidence.
Under Rule 6(e), everyone involved—prosecutors, court reporters, and grand jurors themselves—must maintain the confidentiality of the proceedings. Witnesses, however, are not bound by secrecy and are legally allowed to discuss their testimony unless instructed otherwise (e.g., by a court-issued protective order).
Here's a breakdown of the key players:
Grand Jurors: Citizens drawn from the community who serve for a term that may last up to 18 months. They meet periodically to hear evidence in one or more cases.
Assistant U.S. Attorneys (AUSAs): Federal prosecutors who present evidence, question witnesses, and guide the grand jury through legal standards.
Witnesses: Individuals called to testify, including law enforcement officers, experts, and sometimes targets or subjects of the investigation.
Court Reporter: Records testimony for the official record, though the transcript is not made public unless ordered by a court.
Agents: Federal law enforcement officers (e.g., FBI, DEA, ATF) often assist prosecutors in preparing evidence and subpoenaing witnesses.
There is no judge present, and the defense attorney is not allowed inside the grand jury room during testimony. If a witness has legal counsel, the attorney must wait outside and can only advise the client between questions.
Federal grand juries have broad authority to issue subpoenas for documents, physical evidence, or testimony. There are two types of subpoenas:
Subpoena ad testificandum: Requires a person to appear and testify.
Subpoena duces tecum: Requires a person or entity to produce documents or evidence.
Failure to comply with a subpoena may result in being held in contempt of court. In some instances, individuals can assert their Fifth Amendment right against self-incrimination, although the government may offer immunity to compel testimony.
If you are called before a federal grand jury, it's crucial to understand your status in the investigation:
Witness: Someone with relevant information but not suspected of wrongdoing.
Subject: A person whose conduct falls within the scope of the investigation but who is not necessarily a target.
Target: A person against whom the prosecutor believes there is substantial evidence linking them to a crime.
If you receive a grand jury subpoena, you should immediately consult a federal criminal defense attorney, especially if you are a subject or target.
Federal prosecutors wield significant power during grand jury proceedings. They decide what evidence to present and which witnesses to call. Unlike trial proceedings, there is no requirement to present exculpatory evidence (i.e., evidence that might show the accused is innocent), though ethical guidelines strongly recommend it.
Because grand jurors typically hear only one side of the case—the government's side—the process heavily favors the prosecution. In fact, the often-cited legal adage is that a prosecutor could “indict a ham sandwich.”
After reviewing the evidence, the grand jury votes on whether to return a “true bill” (i.e., an indictment). At least 12 jurors must agree for an indictment to be issued.
If the grand jury votes not to indict, the result is called a “no bill,” and the matter is generally closed unless new evidence emerges.
An indictment does not mean someone is guilty—it merely means the grand jury believes there's probable cause to formally charge the individual and move forward to trial.
While rare, there are some legal grounds to challenge grand jury proceedings:
Improper conduct by the prosecutor
Unlawful use of subpoenas
Violation of secrecy rules
Discriminatory selection of jurors
However, courts are very reluctant to interfere with grand jury proceedings, and challenges are typically difficult to win.
The consequences of a federal grand jury investigation can be life-changing. Even being subpoenaed as a witness can signal serious legal exposure. If you or your business receives a subpoena, do not ignore it, and do not go it alone—consult a criminal defense lawyer experienced in federal matters.
Understanding the purpose and power of grand juries can also empower everyday citizens to be more informed participants in our legal system. Grand jurors themselves serve a critical civic function and are key players in the protection of justice and liberty.
Federal grand jury proceedings sit at the intersection of secrecy, power, and constitutional rights. While the process may seem mysterious or intimidating, it serves an essential role in safeguarding against arbitrary prosecution and upholding the rule of law.
However, the lack of transparency and absence of defense counsel inside the grand jury room means individuals targeted by federal investigations are often at a significant disadvantage. Knowing your rights—and exercising them wisely—is the best defense in any encounter with the federal criminal justice system.
If you've received a federal subpoena or believe you're under investigation, speak to a knowledgeable federal criminal defense attorney immediately. The earlier you get legal advice, the better your chances of protecting your rights and preparing an effective defense.
About the Author
Karren Kenney is a seasoned federal criminal defense attorney with over 20 years of trial experience, including representation in complex white collar investigations, grand jury subpoenas, and federal indictments. Her mission is to defend the constitutional rights of individuals and businesses facing the overwhelming power of the federal government. Attorney Karren Kenney offers a free phone consultation and can be reached at 855-505-5588.
