A Grand Jury is a panel of eighteen (18) Jefferson County citizens selected at random from the pool of regular trial jurors. The panel serves for an entire Session of the Grand Jury, which is three months, and will meet for one week during each of those months. Special sessions of the Grand Jury can also be scheduled as needed. Grand jurors selected for special sessions usually serve only one week.

The purpose of the Grand Jury is to hear and review the State's evidence to determine if there is probable cause to issue an indictment against a suspect. In Alabama, an indictment must be recommended by a Grand Jury before any felony case can go to trial.