It that how you gain trust in a LE organization? By covering up the illegal actions of your "brothers" (or sister, in this case.)
Yes, been there, got out. I thought the best revenge is living well, and I have. The level of corruption I experienced was small potatoes compared to the LAPD. I know other people that have been victimized by corrupt police/LE management. I am not surprised that someone decided to go postal.
Dorner seems to be a kind of worst case. Here he was, mid-career in the Naval Reserve. He refused to go along with a cover-up, and management closed ranks and got rid of him. That cost him his LE career. Because of the lying charge, that cost him his military clearance, which cost him his military career. So here he is, at 33, no prospects because of a corrupt system.
He likely has had pretty good treatment otherwise because of affirmative action, which makes his treatment by the LAPD all the harder to take.
On LAPD corruption:
The LAPD had a policy of legally stealing any gun they came across, for many years. They would confiscate any gun they came across, and refuse to give it back until they got a court order. Court orders cost (lawyers fees) about $2,000 or more. Most guns cost less than that, so almost no one could afford court orders. Legalized theft as department policy.
I have not heard anything lately, so I do not know if the policy continues. I know the NRA had a lawsuit against the practice.
Police need to be held to high ethical standards. When they lie, they undermine the entire fabric of the justice system. The will be held to higher standards in the future, because technology is making it much harder to get away with the lies.