I don ' t understand your first question . Your comment assumes that TPS needs to demonstrate the effectiveness of its investigative tools . I don ' t think they really need to justify utility of the database . They have an obligation to be efficient , but I give them a pretty long rope to figure out creative ways to police . Lord knows criminals aren ' t so constrained . But one more comment , people like to point out how the police have failed to show how carding is effective or how many cases has carding solved . Even if they were required to cough this up , what are the metrics of efficacy ? When are cases even solved ? When there ' s an arrest , a conviction ? Your last point is chicken or egg . Are minority groups over policed out of a confirmation bias or are police investigating or responding to actual crime ? I don ' t know .