Discrimination based on race is illegal, but police still care about race in both official and unofficial ways. And for example, witness testimony of "I saw a

Discrimination based on race is illegal, but police still care about race in both official and unofficial ways. And for example, witness testimony of "I saw a white man leave the scene of the crime" would be completely admissible testimony in a trial. So this doesn't seem like a mistake of worldbuilding to me. The way it's used in the story, it probably says some unflattering things about the police force and the society, but that seems entirely intentional.