You are dead on target about fixing responsibility. While elected officials are relatively remote and return to their districts only under controlled circumstances, cops are the everyday face of the state: on the beat, on foot, or in patrol cars. What they do, while controlled from above, still has a large element of serendipity, and as long as they have guns--and use them--will be viewed suspiciously by many who might otherwise welcome their protection. It's easy to blame the police for the sins of their masters, but they bear considerable responsibility as well. As you know, the prevailing political culture of the police is to belittle the constraints on their activity dictated by the Constitution and subsequent court decisions. In fact, the Supreme Court after Earl Warren's reign has made it possible to move toward the presumption of guilt by enabling police to perform various types of preemptive searches and seizures, provided they can show probable cause. The ACLU and other civil libertarians are beside themselves about this unwarranted extension of police power.
Here's the rub. My son says he is grateful for the ability of Giuliani and the police to make New York safe for his 15-year-old son to move, with minimum threat of harm, around downtown and midtown Manhattan. He has trouble understanding the price we have all paid for individual safety: the steady erosion of basic rights to all. That New York has become an armed camp of legitimate authorities in which the ordinary citizen is often criminalized, on principle, is a matter of little concern for many for whom crime-free streets is the highest value. I don't want to say that safe streets are unimportant. But I must confess that, given the choice, I would prefer a libertarian solution.
Despite the cosmetic efforts to make the police more polite after suffering the Diallo backlash, the mayor and his minions still insist on keeping the basic policy of terrorizing the underlying population. If the administration were seriously interested in addressing the larger issue, notwithstanding maintaining control over the means of violence, it would take steps to change the culture of blaming the citizen before the trial. While you are right to insist that critics allow the four cops their day in court before judging them, distrust will not be attenuated, let alone disappear, until citizens have a louder voice in shaping police policy and the police themselves view the adversarial relationship with large groups of citizens as occasional and not routine.