Prosecutors, judges, law enforcement agents all belong to the same group: so, they collude in the name of co-operation; they are paid by the government. They are the enforcers of "state monopoly on violence". Usually, these folks (prosecutors, judges, LE agents) don't want to step on the powerful elite, as the latter can take these cases all the way to SCOTUS to clamp down on abuses. That's why prosecutors use "prosecutorial discretion" to NOT prosecute so that these cases won't get appealed further.
When elites splinter into two groups, that's when you see some progress. Otherwise, two-tier justice is a common, hidden, feature of any system out there (be it Western democracy, communist, dictatorship, etc).
When elites splinter into two groups, that's when you see some progress. Otherwise, two-tier justice is a common, hidden, feature of any system out there (be it Western democracy, communist, dictatorship, etc).