Strap 'em all to a lie detector machine and ask:

Ever ticket a speeding cop?
Ever ticket a kid, doctor, lawyer, or any one just because they were younger and richer. Even smarter than you? 
Ever commit a felony and get away with it because cops protect each other?
Will you put suspicious cops on unpaid leave if they are suspected of getting overtime for phony court summons?
Ever beat up or shoot someone just because you lost your temper?
Ever point your gun at an unarmed person or shoot someone when it wasn't necessary? 
Will you take a spelling test and an SAT test? 
Would you give a governor a personal gun carry permit even if it was against the law? 
Have you ever rushed above the speed limit to a crime/accident scene and then stood around telling fishing stories and shooting the bull to take advantage of overtime?
Will you stop overtime once and for all? How will you do this?
What is your plan to stop prostitution, undesirables, and homelessness for good? 
Eradicate fat cops/donut