GENERAL PART
Chapter II EFFECT OF THE PENAL CODE
Article 7.- The temporal application of the Penal Code
2. Provisions defining a new offense, a heavier penalty, a new aggravating circumstance or restricting the scope of application of suspended sentences, the exemption of penal liability and/or penalties, the reduction of penalties or remission of criminal records, and other provisions not in favor of the offenders, shall not apply to acts of criminal offense committed before such provisions take effect.
EDIT.