CPAC stand for Civilian Police Accountability Council. In others words, it means civilian control of the police force.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/74207111@N00">Charles Edward Miller</a> from Chicago, United States
CC BY-SA 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/cemillerphotography/39721195393/">Jedidiah Brown for the 7th Ward City of Chicago Aldermanic Candidates Press Conference to Support Civilian Police Accountability Council Chicago Illinois 1-9-19 5578</a>