Most of the high-profile cases of alleged police abuse today are caught on tape by people who happen to be walking by. But there's also an organized movement of "cop watchers" who consider it their jobs to police the police.
In places like Texas, tensions are growing and police are pushing back.
This story is part of a collaboration between The Texas Tribune and Reveal, a new public radio show and podcast from the Center for Investigative Reporting and PRX. Michael Montgomery of Reveal contributed to this report.