The refusal of some police officers to report fellow officers' misconduct is called:

The refusal of some police officers of having to report their fellow officers who has performed misconduct is called the blue wall of silence. The blue wall of silence is also known as blue code in which the police officers has an unwritten rule of having to keep it to themselves or not report their fellow mates with the things that their fellow office mates that they have done in which are crimes, errors and other things that they shouldn’t be doing as a police officer.