Yes. But... The purpose of a policeman is not to interpret the law but to enforce it. This doesn't excuse all evil behavior but some of it. Do we allow "x" in a public area. You may think yes it's fine; others may disagree. Ultimately hire politicians to make laws which we - as the public supposedly agree with; which the courts have upheld as constitutional. Does the policeman have the leeway to say that he won't enforce the law?
Hitting a child used to be common. If we pass a law saying that using a belt on your child is illegal can the policeman chose to ignore it if he sees it? The same all goes for drugs. What can and cannot be allowed is not determined by the police.
What we need to do is have the politicians accountable as well. The Minneapolis City Council and Mayoral office had oversite responsibility on the police departments rules and procedures. They signed off on kneeling on necks - and yet no one holds them accountable.