In the United States at least, it's already been argued and won in court that the police have no duty to serve and protect. If you call up because your kids are about to be murdered, and they do absolutely nothing for 4 days, and your kids are in fact murdered, well I guess you should have raised less murderable kids.

I've got respect for many police. There are people who walk towards situations that many of us would run away from and have to deal with the thankless task of dealing with situations without a win scenario. Regardless, the institution itself is no less corrupt than any other government institution.