I recently had a disagreement with a non-libertarian about police corruption. He is from Latin America but is currently living in Miami. It is his assertion that “police corruption outside of the largest cities is virtually non-existent in America” and that it is not in any way comparable to that in places like Mexico and Guatemala.
In Latin America, and in much of the world, police corruption, even if we are only talking about mordidas (small bribes) to get one out of a traffic ticket, are widely accepted. Everyone knows it takes place and everyone knows that the police are corrupt. In the United States things are a bit different as so much of the populace, despite all of the evidence to the contrary, do seem to put law enforcement officers on a lofty, undeserved pedestal. If anything, this just makes it easier for those in positions of power to act outside of the law (or even just common decency) in the United States.
Not only does an immigrant from Mexico not have to go all the way to Chicago, Los Angeles or New York City to find corruption; he can probably find it at every border crossing separating the two nation-states.
The U.S. government is spending huge sums tightening border security so gangs that import marijuana and other prohibited items are able to charge more and, as it turns out, able to offer much more to Border Patrol agents than the $70,000 per year that they receive via their taxpayer-extorted salaries. And despite what the “reality” shows have tried to tell us, Border Patrol recruits are not exactly the cream of the crop.
As one exasperated investigator at the border put it, “There is so much hiring; if you have a warm body and pulse, you have a job.” LINK
As Lord Acton said “All power tends to corrupt; absolute power corrupts absolutely.” Note that there is nothing about geography in that old axiom.
J Nick Puglia has been a small 'l' libertarian since the mid-90s. He travels around the Pacific Northwest in his RV selling jewelry, playing cards, drinking wine and preaching the virtues of a stateless society. Nick is the 
Police corruption in the USA is different from that found in Mexico and other countries. I’m not sure what to say about it to someone who is living in Miami, though. If he’s convinced that life is paradise in smaller communities, he ought to give it a try for a few years.
Prostitution, gambling, drugs, fencing stolen property, and many other activities are known and tolerated in smaller cities and towns. The process for working the system is different, but corruption is there. Often, it isn’t all that hard to find.
Take, for example, Terre Haute, Indiana. I was able to find 147,000 hits off Google on “corruption Terre Haute IN” as a search term.
The top link suggests one type of corruption is “statistically based enforcement funding” for example DUI checkpoint arrests. Many prosecutors are paid for percentage of “successful” prosecutions, so they lie and cheat their way into plea bargain agreements. One of the next few links is an editorial on corruption in lobbying at the statehouse in Indianapolis.
I picked on Terre Haute because Steve Martin did.