It's possible in some jurisdictions although as you say they can very easily be unjust. https://en.m.wikipedia.org/wiki/Ex_post_facto_law https://en.m.wikipedi

It's possible in some jurisdictions although as you say they can very easily be unjust. https://en.m.wikipedia.org/wiki/Ex_post_facto_law https://en.m.wikipedia.org/wiki/Ex_post_facto_law