This amounts to guilt by association.  If you associated with a few disfavored gene sequences, you're guilty.

How could anybody ever hope to confront the witnesses against him with such information being accepted as evidence.

However well or poorly, guilt or innocence has been based on actions, actions demonstrated by evidence.

How can any gene sequence be used as evidence of an act?

I think individual actions grow out of attitudes long held and choices made in the moment.  I think that individual will does not inevitably grow out of DNA.

DC Treybil

Unless they find it in high proportion in politicians, judges and prosecutors like last time they had a criminal gene --- which proved its accuracy BTW.

 "Wizards" calling themselves by various names have nearly always said what the "Kings" (who also were referred to by a variety of names) what the "King" wanted to hear.

Likely, this tendency is even more pronounced today due to natural selection.

DC Treybil