To verify the occurrence of a singular instance of testimonial injustice three facts must be established. The first is whether the hearer in fact has an identity prejudice of which she may or may not be aware; the second is whether that prejudice was in fact the cause of the unjustified credibility deficit; and the third is whether there was in fact a credibility deficit in the testimonial exchange. These three elements constitute the facts of the matter of testimonial injustice. In this essay we argue that none of these facts can be established with any degree of confidence, and therefore that testimonial injustice is an undetectable phenomenon in singular instances. Our intention is not to undermine the idea of testimonial injustice, but rather to set limits to what can be justifiably asserted about it. According to our argument, although there are insufficient reasons to identify individual acts of testimonial injustice, it is possible to recognize recurrent patterns of epistemic responses to speakers who belong to specific social groups. General testimonial injustice can thus be characterized as a behavioral tendency of a prejudiced hearer.