CHAPTER III
PROTECTION OF FUNDAMENTAL RIGHTS AND FREEDOMS OF THE INDIVIDUAL

18. Provisions to secure protection of law.

(4) No person shall be held to be guilty of a criminal offence on account of any act or omission that did not, at the time it took place, constitute such an offence, and no penalty shall be imposed for any criminal offence that is more severe in degree or nature than the most severe penalty that might have been imposed for that offence at the time when it was committed.