That’s the blue wall that you hear about.
No “decent” cop wants to be seen as being outside of the pack because he’ll end up without backup or taking a bullet from one of the scumbags supposed to be covering him.
In other words, he accepts the bad behavior because it’s safer than doing what’s right and by keeping his mouth shut encourages these outrages.
There are no “good” cops in a dirty department. Broom the whole place and start from scratch, it’s the only way to eliminate the corrupt and power crazed.
The solution is easy to conceptualize; higher eligibility standards (fewer dumbass, psychologically flawed cops), better training, and a higher level of personal accountability at every level of the police departments.