PART II: FUNDAMENTAL PRINCIPLES OF STATE POLICY
35. Protection in respect of trial and punishment
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 charged as an offence , nor be subjected to a penalty greater than, or different from that which might have been inflicted under the law in force at the time of the commission of the offence No person shall be prosecuted and punished for the same offence more than once.

Every person accused of a criminal offence shall have the right to a speedy and public trial by an independent and impartial court or tribunal established by law

No person accused of any offence shall be compelled to be a witness against himself. No person shall be subjected to torture or to cruel, inhuman, or degrading punishment or treatment .Nothing in clause (3) or clause (5) shall affect the operation of any existing law which prescribes any punishment or procedure for trial.