A grand jury is used in federal court all the time, and in many states for certain crimes. A grand jury is simply a group of citizens, usually between 16 and 23, that act as rubber stamps for prosecutors to indict people. There's a common saying that, "A grand jury will indict a ham sandwich." The bottom line is grand juries do whatever prosecutors want them to do, if they wanna get an indictment against someone, the grand jurors vote for an indictment. If the grand jurors don't want to indict someone, for example, police officers, grand juries don't indict police officers. Grand juries are a farce and a mockery, but an important part of our criminal justice system. If you've been subpoenaed either as a witness or a subject or a target, to a grand jury, it is absolutely essential that you be represented by an experienced criminal defense attorney who understands how to handle grand jury matters.