The right not to be found guilty of a retrospective criminal offence in s. 27(1) is qualified by s. 27(4).

As with all of the human rights protected in the Charter, the right under s. 27(1) may also be subject to reasonable limitations that can be demonstrably justified in a democratic society in accordance with s. 7 of the Charter. You should refer to Part 2 of these Charter Guidelines for further information on s. 7.