Final answer:
Prosecutors obtain an indictment through a grand jury proceeding. The grand jury reviews evidence and determines if there is probable cause for a trial regarding serious crimes, in accordance with the Fifth Amendment. States may use alternative methods, such as preliminary hearings, for the same purpose.
Step-by-step explanation:
Prosecutors obtain an indictment through a proceeding involving a grand jury. This process is integral to the American criminal justice system and adheres to the provisions of the Fifth Amendment, which requires that serious federal criminal charges, such as felonies, be initiated only after a grand jury determines there is sufficient evidence to justify a trial.
States have their own systems, where they may use preliminary hearings instead of grand juries to establish whether sufficient evidence exists for a trial. The grand jury, which comprises a group of citizens, reviews evidence presented by the prosecutor and decides if it establishes probable cause to believe that a crime was committed and that the accused committed it.