The aim of this study was to examine applicant and method factors related to ethnic score differences on a cognitive ability test, a personality test, an assessment center (AC), an employment interview, and a final employment recommendation in the context of police officer selection (N = 13,526). Score differences between the majority group and the first-generation minority groups were comparable to research findings from the literature. However, score differences between the majority group and second-generation minority groups were much smaller. On the cognitive ability test and the personality test most variability was explained by Dutch language-proficiency. Confirming assumed-characteristics theory, more variability on the interview and the employment recommendation was explained by Dutch language-proficiency and education than on the AC. Unsupportive of complexity-extremity theory, there seemed to be a general tendency to give lower scores to the ethnic minority group.The personnel selection literature has extensively investigated differences on psychological measures between ethnic minority and majority groups. This study focuses on ethnicity-related applicant demographics, such as language-proficiency and education, and their interplay with selection-method factors in their impact on test scores.