Stereotypes linking Black Americans with guns can have life-altering outcomes, making it important to identify factors that shape such weapon identification biases and how they do so. We report 6 experiments that provide a mechanistic account of how category salience affects weapon identification bias elicited by male faces varying in race (Black, White) and age (men, boys). Behavioral analyses of error rates and response latencies revealed that, when race was salient, faces of Black versus White males (regardless of age) facilitated the classification of objects as guns versus tools. When a category other than race was salient, racial bias in behavior was reduced, though not eliminated. In Experiments 1-4, racial bias was weaker when participants attended to a social category besides race (i.e., age). In Experiments 5 and 6, racial bias was weaker when participants attended to an applicable, yet nonsubstantive category (i.e., the color of a dot on the face). Across experiments, process analyses using diffusion models revealed that, when race was salient, seeing Black versus White male faces led to an initial bias to favor the "gun" response. When a category besides race (i.e., age, dot color) was salient, racial bias in the relative start point was reduced, though not eliminated. These results suggest that the magnitude of racial bias in weapon identification may differ depending on what social category is salient. The collective findings also highlight the utility of diffusion modeling for elucidating how category salience shapes processes underlying racial biases in behavior. (PsycInfo Database Record (c) 2021 APA, all rights reserved).