The legal system shouldn't work (think) this way. A lot of criminals should go free because no real crime was proven. That's the point.
If the nation doesn't see the point it doesn't use the real legal system. The legal system is about rights. If the rights aren't important to you, you may have Linch, of fashist Italy (Mussolini) model.
https://disqus.com/home/channel/disqusunderground/discussion/channel-disqusunderground/san_francisco_to_expunge_thousands_of_marijuana_convictions/#comment-4355776729