Neuroscience evidence is appealing as a means to increase “objectivity” and reduce racial disparities in the criminal legal system. However, increasing reliance on defendants’ brain data may instead maintain racial disparities while rendering biases invisible. First, neurobiological data are not any more objective than traditional psychological measures. Second, the complexity and inaccessibility of neuroscience undermines public understanding of what such data can actually say. Third, existing methodologies have limitations when working with hair types and skin colors that are socially coded as Black; these phenotypic biases reduce both the reliability of individual data and the representativeness of comparison groups, skewing interpretations of defendants’ brain data. More research is needed before neuroscience evidence can be considered more probative than prejudicial.