There's guilty, where you have evidence that points to a suspects guilt, and then there's (for example) "I did this thing in full view of 100 people and cameras" guilty. That's already pretty big difference between levels of assurance of guilt.

As I said before, I can't come up with legal, concrete, and objective measures because I haven't studied law. It's completely unreasonable for you to ask that. Furthermore, as a taxpayer and regular voter, I help fund and choose the people that have said training. It's up to them to figure out how to implement a solution. I can't be expected to do everything.