Part III — Fundamental Rights
No person shall be convicted of any offence except for violation of a law in force at the time of the commission of the act, nor be subjected to a penalty greater than that which might have been inflicted under the law in force. No person shall be prosecuted and punished for the same offence more than once. No person accused of any offence shall be compelled to be a witness against himself.
Three protections for the accused: no punishment under a law made after the act (no ex-post-facto law), no double jeopardy (punished twice for the same offence), and no self-incrimination (cannot be forced to testify against yourself).