Not the same thing as a trial jury, and not a group that decides whether someone is guilty. A grand jury is a panel of citizens asked to review evidence presented by a prosecutor and decide whether there is enough probable cause to bring a serious criminal charge, usually by issuing an indictment. The process is typically private, the rules of evidence are looser than at trial, and the person under investigation usually does not have the same chance to challenge witnesses that they would later in court.

That difference matters. A grand jury only answers a charging question: is there enough evidence to move forward? It does not decide guilt beyond a reasonable doubt. In practice, that means a case can begin with an indictment and still later end in dismissal, plea bargain, or acquittal. For someone accused of a crime, understanding that stage helps explain why early statements, records, and witness accounts can shape the case before a defense is fully presented.

In Iowa, felony prosecutions often proceed by trial information rather than a grand jury indictment under the Iowa Rules of Criminal Procedure. Grand juries are still available, but they are not the only charging path. That can affect timing, strategy, and how quickly a criminal case starts. If an accident leads to both criminal allegations and a civil injury claim, the evidence developed during charging can influence settlement positions, witness credibility disputes, and later arguments about fault.