Campaign Zero launched the Check the Police initiative to increase transparency and accountability within police departments. This project focused on analyzing and publicizing police union contracts and policies that often shield officers from accountability. By highlighting these issues, Check the Police aimed to empower communities and activists to advocate for reforms that ensure police accountability and promote justice. This initiative played a crucial role in the broader movement to address systemic problems in law enforcement.

Check the Police, the first iteration of Nix the 6, allowed organizers to easily identify problematic provisions in police union contracts and facilitated long-term research initiatives to understand the impact of collective bargaining agreements on policing outcomes.