Therefore, an act or omission, which today is not an offence and someone commits such act or omission will be doing it on faith that such an act or omission is not an offence, however, if tomorrow govt. declares it an offence then it would make everyone who committed such act or omission today an offender, if retro-activity applied to criminal laws. read more
Laws have never been, and will never been applicable with retroactive effect in case of criminal laws. And the reason for this is quite simple actually. Criminal law exists to punish you for something you have done (or not done something you should have) which is a legal wrong today. read more
According to the 5th Article, section XXXVI of the Brazilian Constitution, laws cannot have ex post facto effects that affect acquired rights, accomplished juridical acts and res judicata. The same article in section XL prohibits ex post facto criminal laws. Like France, there is an exception when retroactive criminal laws benefit the accused person. read more