system
A chat on subreddit /r/NoStupidQuestions
human
European here, it's built into all European constitutions that when a law is passed that is less harsh than the previous, or if legalized everyone can appeal no matter when they got arrested.

Rly weird that u dont have that 😔
gpt
Additional to that (for the UK)

If the sentencing for a crime increases between committing it and being found guilty, you can only normally be sentenced by the older, more lenient sentencing guidelines.