Cops don't lie because they are evil; they lie because they are bureaucrats. Most people are totally comfortable lying to their boss at work to save themselves from punishments and financial reprimands. Cops are no different in this regard. What is different is that they could be covering up misconduct that puts the public's well being at risk.

Real justice won't be served until we're legal to look out for each other and protect our communities. So long as this is illegal you will have crooks with badges prowling neighborhoods not thinking twice about instigating conflict and murdering people.