The Key Differences Between a Federal Grand Jury vs a Grand Jury Indictment

A grand jury plays an important role in the criminal justice system, but it functions very differently from a trial jury. Here are some of the key differences between a federal grand jury and a grand jury indictment:

Role and Purpose

• A federal grand jury determines whether there is probable cause to charge someone with a crime and bring them to trial. They decide whether to issue an indictment[1][2].
• A trial jury (also called a petit jury) determines whether the defendant is guilty or not guilty at the actual trial. They decide the verdict[1][2].

So the grand jury is focused on the preliminary charging decision, while the trial jury makes the final determination of guilt or innocence.

How They Are Convened

• Grand juries are convened for set terms – like 12 or 18 months. During that time, they will hear evidence on multiple different cases[4][5].
• Trial juries are convened solely for one specific trial. They only hear evidence related to that single case[2].

This means grand jurors will gain experience over their term, while trial jurors are coming in cold to each new trial.

Number of Jurors

• Federal grand juries have 16-23 jurors[2].
• Trial juries in federal criminal cases have 12 jurors[2].

So a grand jury is a larger body. This allows for some absences while still having a quorum.

Unanimity

• Grand jury indictments do NOT need to be unanimous – only 12 of the 16-23 jurors need to vote in favor[4].
• Trial jury verdicts in federal court MUST be unanimous – all 12 jurors must agree[4].

So there is a higher bar for consensus on a trial jury.

Privacy

• Grand jury proceedings are conducted in secret[1][3][4]. Only the jurors, prosecutor, judge, witnesses, and court staff are present.
• Trial jury proceedings are generally public[4]. The jury deliberations are private, but otherwise the trial itself is open.

This secrecy for grand juries is meant to protect the confidentiality of the investigation.

Attendees

• The defendant and their attorney cannot attend grand jury proceedings[3][4]. Only the prosecution presents evidence.
• The defendant and their attorney are present for the entirety of a trial jury proceeding, able to see all evidence and cross-examine witnesses[4].

So grand jury proceedings are decidedly one-sided, while trial proceedings allow robust participation from both sides.

Introduction of Evidence

• Grand juries can hear any evidence the prosecutor wants to present, even illegally obtained evidence[4]. There are no evidentiary rules.
• Trial juries can only hear evidence that meets the strict evidentiary rules for admissibility in court[4].

So evidence before a grand jury faces little scrutiny compared to a trial jury.

Standard of Proof

• Grand juries use the “probable cause” standard. They only need to find it reasonably likely that the defendant committed the crime[1][3].
• Trial juries use the “beyond a reasonable doubt” standard. Guilt must be proven to a very high degree of certainty[1][3].

The standard is thus much lower for a grand jury to indict than a trial jury to convict.

Role of the Prosecutor

• The prosecutor takes the lead in grand jury proceedings, presenting witnesses and evidence how they choose. The grand jury is passive[3][4].
• The prosecutor and defense attorney play equal roles at trial, both able to call witnesses and introduce evidence[4]. The trial jury takes an active role.

So grand juries rely heavily on the prosecutor’s guidance, while trial juries serve as a more independent body.

Binding Effect

• Grand jury indictments are not binding on the prosecutor. The prosecutor can choose to dismiss charges even if the grand jury votes to indict[2].
• Trial jury verdicts are legally binding results that strictly determine the outcome of the case[2].

So the grand jury gives recommendations that the prosecutor can disregard, while the trial jury makes definitive decisions.

Conclusion

While both grand juries and trial juries are comprised of impartial citizens weighing criminal allegations, they serve very different purposes in very different settings. Grand juries operate in secret, hear only the prosecution’s side, use a lower standard of proof, and issue non-binding indictments. Trial juries operate openly, hear from both sides, use a higher standard of proof, and issue legally binding verdicts. Understanding these key differences is important for anyone involved in the criminal justice process.