User blog comment:Gundam Legilis/Diary 2/@comment-86.150.94.227-20140404183425/@comment-3387274-20140405141310

In their defence, if you accuse a human who is anti faunus of being one, then from their perspective you've just hurled a mortal insult. That wouldn't be wise to risk if you didn't have evidence...

Of course, it might just be that nobody conected Blake herself to any crimes. If they knew she was a Faunus you  might pick up the pieces, and notice that a girl with a bow seems to be in the area every so often. But the police don't know the trick and just assume that she's human and would never be with the WF.