That is a very long email filled with a lot of waffle which is based on things you seem to be worried about due to not understanding the situation. I'm not helping you with everything but read what you're typing, you've put a post about needing explicit consent to use DNA and then made up a story that people can be tricked. Not how it works.
The screenshot you've found of Gedmatch isn't anything to do with police at all.
Finally, you've claimed I haven't answered the court case suggestion, which I did a message or two ago. If they have a case strong enough to get your DNA then they can get it from you. No need to go faffing about with websites.
To use genetic genealogy you need access to a database of users, each of those peoples data is protected and in order to use them each time you would need to make a valid case for each persons DNA. That means hundreds of thousands individual cases and you wouldn't get permission as theres no cause.