We're halfway there, data mining by insurances already is the norm in car insurance. We should have fought back hard back in the day this was proposed.
> I haven't murdered anyone, so I'm not worried about getting caught up in a DNA dragnet. Sure, there can be false positives, but to get on in life you pretty much have to ignore events with low statistical probability
Even if you haven't murdered anyone or intend to to so - your genetic data is useful in the pig dragnet. Your genetic data may be what provides the pigs with a link to your nephew who moonlights as a graffiti sprayer... and yes, the German pigs are doing DNA checks on graffiti sprayers, they have been doing so for over two decades [1].
[1] https://www.welt.de/print-welt/article398332/Graffiti-Erstma...