It is (probably) impossible to write down a complete list of rules for how to judge even petty crimes. Someone who steals a loaf of bread because their child is starving should not be punished the same way as someone who steals a loaf of bread because they're a kleptomaniac.
No two situations are identical, and the problems start when you try to come up with a one-size-fits-all approach.
A human with sound judgement (and, arguably, some empathy) should be in control.
