Which of the following is not correct with regard to the grand jury?

The statement regarding a witness being accompanied by his or her attorney is not correct in the context of grand jury proceedings. In most grand jury situations, witnesses are not allowed to have their attorneys present during their testimony. This is due to the nature of grand jury investigations, which are designed to evaluate evidence and determine whether there is enough cause to charge someone with a crime. The secrecy of the proceedings and the format of questioning are structured in a way that encourages full disclosure without the potential influence or guidance of legal counsel.

In contrast, the other statements about a grand jury are accurate. A federal grand jury indeed consists of 16 to 23 jurors, reflecting the requirements set by federal law. The proceedings are fundamentally secret, which protects the integrity of the investigation and the identities of the witnesses involved. Furthermore, the primary role of a grand jury is to assess whether there is probable cause to believe that a crime has been committed, which is a critical part of the criminal justice process as it determines whether a case moves forward into formal charges.