Yes, I believe I can sometimes read minds, and I'm willing to bet you can, too.
If you see a guy climbing in your teenage daughter's bedroom window in the middle of the night, with rope and a butcher knife in his hand, do you believe you have a pretty good idea what he's thinking? Or should you wait and ask him before making any snap judgments?
At the risk of triggering those who misapply Godwin's Law, do you have a good idea what was going through the mind of some random guy in Germany around 1940, who joined the Nazi Party, proudly wore the regalia, and enthusiastically participated in the rallies, and never objected to what was being done by other members of his gang (and never tried to stop it and didn't quit in disgust)?
In the same way, if someone voluntarily joins the Blue Line Gang, wears the uniform and other identifying items, do you know his mind?
Do you honestly believe he could keep the "job" without violating anyone, ever. Or, is that a condition of employment? Even if he never commits a traffic stop, never steals money with a parking ticket, never kidnaps or robs anyone over drugs, guns, gambling, or prostitution, is he still guilty?
That's ignoring the fact that the money he "earns" is stolen.
Maybe, when he first decided to be a cop, he had only good intentions. (You'll need to read his mind to see if this is true.) But as soon as the realities of the "job" intrude, he has a choice to make: Keep doing the "job" and remain a member of a gang which only exists because it exercises the power to aggress and violate property rights, or quit and find honest employment. What is going through his mind now? Is he consciously making the choice to remain a cop?
And really, what does it matter what is going through his mind?
Back to the guy climbing in your daughter's window, isn't the fact of his actions enough to make it right for you to defend your daughter from him? What he's thinking-- what he believes about what he's doing-- is irrelevant. Why should cops be treated differently than anyone else on the planet? Why do I have to prove that I know what they are thinking while they are molesting people?