Louisiana constitution
Article 1
Section 15

Prosecution of a felony shall be initiated by indictment or information, but no person shall be held to answer for a capital crime or a crime punishable by life imprisonment except on indictment by a grand jury. No person shall be twice placed in jeopardy for the same offense, except on his application for a new trial, when a mistrial is declared, or when a motion in arrest of judgment is sustained.