It's easier for evidence to say the person is innocent than guilty. Ex: a blurry video of a white guy. It's in no way enough to show which white person did it, but it is enough to show no black person did.

The top comment under which my comment falls is about police use of forensic "science".

>The big crime is how little epistemological support there is for some of the big forensic tools (fingerprints, DNA, bite marks, arson spread, etc), how little interest there is in researching these areas, and how trusted they are. But I am curious: apart from TV shows, how important is this kind of evidence in most trials? Is it actually uncommon?