[yibg]

I think it's a combination of a few things:

1) Institutional and culture view of policing, vs say other western countries that are more community policing based.

2) General brotherhood of law enforcement and protecting each other. There is a lack of holding each other accountable.

3) General protection afforded by law, either explicitly or implicitly via half hearted attempts at prosecution / investigation etc.

These combined gives law enforcement as an organization and individuals a sense of normalcy in what they do, and also feeling of invulnerability.

This doesn't apply to all police officers of course, and I actually believe the majority are law bidding and trying to do good in a tough environment. There are probably also a non trivial amount that gets into law enforcement to wield power over others. Law enforcement needs to be held to a higher standard, and because of the power they wield must be scrutinized much more closely.

[akircher]

I would add a self-selection bias for people who decide to pursue a career in policing.