Its a shame that the 90% of good cops are forced to tolerate the abusive and sick ("badge and gun disease") behaviour of the minority.
Let's accept for argument's sake that 90% of ALL cops are "good" (not overtly criminal, given to nothing worse than minor fudging of the rules), that doesn't address SPECIFIC police departments.
I have no particular reason to believe that most people join the Rocky River PD to do anything other than have a career enforcing the law. I don't expect them to be morally pure altruists, merely that they reasonably faithfully uphold the law and protect the public welfare in general. To the best of my knowledge, other than possibly targeting young people for tighter enforcement of driving regulations, they have no reputation more remarkable than that.
The same cannot be said of the Chicago PD. It has a reputation going back more than a HUNDRED years, and it's NOT a GOOD reputation. That being the case, it attracts a certain type of individual. By documented evidence, that individual frequently wants to enrich himself through bribery, extortion or outright theft. He wishes to have and exercise power over others, for no other reason than to gratify his own ego. He wishes to be able to use violence against those whom he hates (or just for its own sake) without fear of legal consequences. Those kinds of people have regularly insinuated themselves into the Chicago PD. Rising within the ranks, they hire and promote the same sorts of individuals. After a HUNDRED years, the Chicago PD self-selects for brutality and venality. It's very much like the molestaton scandal in the Catholic Church. ALL priests aren't pedophiles. But SOME are. Like the Chicago PD, the Church in certain areas is led by those who either condone misbehavior, or who view public knowledge of that misbehavior as worse than the misbehavior itself. In such an environment of concentrated corruption, any individual "good" policeman (or priest) is utterly irrelevant. At best, he will look the other way while not overtly committing crimes himself. But that is an endorsement of the corrupt system itself. Obviously neither Father Geoghan nor Officer Abbate were capable of learning a thing via a positive example... or a hundred.
Just as post-war Germany was "de-Nazified", the Chicago PD needs to be "de-thugified". Unfortunately, there isn't ANY sentiment for that within the Chicago PD, either at the top or in the rank and file. The management philosophy of the Chicago PD is perfectly embodied by [soon to be?] ex-Superintendent Phil Cline, who punished murder with a thirty day suspension, sat on an assault and battery case against the Jefferson Tap cops, and allowed the initial prosecution of Tony Abbate as a misdemeanor. As I noted before, if lower ranking police personnel won't turn in their corrupt contemporaries (and they WILL NOT) there are effectively NO "good cops".
Neither is there the slightest desire for REAL reform on the part of Dick Daley. As things stand, he can use the Chicago PD for his dirty work, and leave them twisting in the wind when they're no longer useful to him. If the Chicago PD weren't dirty, he couldn't order it to let his henchmen go when they're arrested for drunk driving while carrying a concealed weapon with the serial number filed off.
And the citizens of Chicago? The idea of honest police whom the law abiding need not fear is simply as alien to them as wearing one's trousers on one's head.
I have absolutely no illusions that the Chicago PD will ever be anything other than an organized crime family, at least until the people who live in Chicago rise up and refuse to continue to be victims. I see no evidence of any such desire on their part. And the repeated reelection of Richard M. Daley is proof positive.