If the laws seem unjust, poorly crafted, unevenly enforced, or too harshly enforced then the law will not have the support of the people. If the law does not have their support, then the law enforcement authorities will not get their cooperation.

The problem is not celebrities pushing a code of silence. That is a symptom. The problem is one of perception. When you have the pop culture and the politicians telling inner city residents that the laws target them (longer sentences for "black drugs" like crack versus "white drugs") and that the police are out to get them (driving while black, etc), then the people are going to have an adversarial relationship with the police, no matter what - even if the police are trying to prevent or investigate rapes and murders. You can even see a similar dynamic on our roadways - we all know that speed can contribute to accidents and make them more deadly, but many, if not most people, deliberately violate speed limits and help others to avoid getting pulled over and ticketed. Why? Partly because they think the speed limits are too low, partly because they think the enforcement is too harsh, partly because they are special and laws shouldn't apply to them, partly because they don't see anything wrong with breaking the law, and thus they see nothing wrong with helping others to avoid detection.

Until people stop pushing the narratives that blacks are perpetual victims of a racist nation, the "code of silence" problem will remain. Hurricane Katrina was probably the most shameful and damaging instance of this narrative being pushed in quite a while. Government incompetence was portrayed as overt racism and turned into a political issue. Being a Katrina "victim" is now yet another badge of honor that can be worn. It is sad that there are political incentives for making black Americans to the US what Palestinians are to Israel.