An important thing you should recognize: the judicial system is painfully nontransparent in such a way that even figuring this sort of thing takes an extensive amount of time and is often even impossible. I've personally gone down a similar route (did some journalism for a bit) by trying to understand how shotspotter is used in prosecution, many of which resulted in false arrests and many, many years of life lost across all the people arrested falsely from it.

If you would like to begin trying to answer these, I recommend starting with submitting some FOIAs. Considering your stance seems to be that you won't believe what others are telling you -- I promise you that you'll be surprised.