All interesting stuff. The wealthy (and it should be stated that this is very wealthy, not just well off) will and have always had the power. It doesn't matter what Country / Religion / era you go to, it has always been the case.
The difficulty here lies with the laws and Human Rights, rather than trying to blanket-blame any section of Society - in this case, the Police. For sure, there are some "bad-uns" in the force, but show me any other part of the population that is whiter than white. In every line of work, there are good, normal and bad - whether they are the Police, Bankers, Unemployed, Taxi-drivers, Lawyers, Estate agents, Retailers etc. etc. There are, however, 2 key differences - 1) roles such as the Police and Bankers are high-profile and previously (generally) trusted and 2) failings are publicised by the media like never before.
Power and/or Money, will always cause boundaries to be tested. Add across this, an element of opportunity and things get blurred.
For example, look at these 2 questions:
1) You find some money on the floor, outside a library. Do you a) pocket the cash, b) take it into the library and leave it for the rightful to claim or c) take it to a Police station. Now, what happens if the sum of money is £10 / £100 / £1,000 - does your answer change
2) You go on holiday and your suitcase is lost. Do you a) put in a claim to the insurance company for the actual loss, b) add around 20%, assuming that they will try to negotiate your claim or c) double it as a minimum, as insurance companies are evil corporate bodies who deserved to get done big time.
If you've not answered c) (or maybe b) for the first and a) for the second, then are you any better than any other?
The frightening fact is that most people will do wrong, given the opportunity, when there is a reasonable chance of getting away with it. Fraud statistics show that around 10% of people would never do the wrong thing, 10% of people would always do the wrong thing and around 80% would do it, if it didn't seem too bad (e.g. the £100 and 20% inflated claim) if they thought they could get away with it.
Human nature is that people look for an advantage, even if the result of that is disadvantaging someone else.