A grand jury is a type of jury, comprised of citizens who are presented with evidence from a state or federal prosecutor (District Attorney or United States Attorney) to determine whether there is probable cause to believe a person committed a crime and should be put on trial. If the grand jury determines there is enough evidence, an indictment will be issued against the defendant. This is known as a “true bill,” and the grand jury is said to have “returned a true bill.” If the grand jury does not believe there is sufficient evidence the accused committed a crime and should be put on trial, it is said to return a “no true bill" or "no bill."

The United States Constitution does not require states to use a grand jury to bring criminal charges against a person—but many states do use grand juries, and some states are required by their state constitution or statutes to use a grand jury to secure an indictment for any felony criminal offense. And the U.S. Supreme Court has interpreted the Constitution to require the federal government to use grand juries for all felony crimes.

Grand jury proceedings are not open to the public and accused persons and their attorneys do not have the right to appear before the grand jury, or to be informed of the proceedings. Witnesses subpoenaed by a grand jury do not have the right to have their attorney present during their testimony. The grand jury proceedings are generally transcribed by a court reporter, but the record is sealed.

Federal grand juries generally consist of 16-23 persons who serve or work on the grand jury for a few days each month for approximately one year—after which a new grand jury is selected by the Federal District Court. At least 12 jurors must agree to return a true bill for indictment of the accused person.

Procedures for the use of grand juries in the state court system vary from state to state and are generally governed by the state’s constitution, and statutes that are often located in the penal or criminal code, the code of criminal procedure, or the government code.

In Nebraska, grand juries are used in accordance with state law, which is guided by the Nebraska Revised Statutes. The state mandates the use of grand juries for certain types of cases, such as when a person dies while in custody of law enforcement or while being apprehended, or when a public official is involved in misconduct related to their office. Nebraska grand juries are composed of 16 citizens, with 12 votes required to return a true bill of indictment. The proceedings are secretive, and neither the accused nor their attorneys have the right to be present or informed about the proceedings. Witnesses cannot have their attorneys with them during testimony. The federal system also uses grand juries for all felony crimes, as required by the U.S. Constitution, and these typically consist of 16-23 members who serve for about a year, with at least 12 jurors needed to indict. The specific procedures and requirements for grand juries in Nebraska are detailed in the state's statutes, which outline how they are to be convened, the scope of their authority, and the manner in which they operate.