As you may have heard a grand jury recently declined to bring charges against Ferguson police officer Darren Wilson who fatally shot Michael Brown on August 9, 2014. Most of the evidence the grand jury heard before reaching this decision has been released and is available here. I have not examined this evidence in great detail but the case that Wilson acted criminally appears weak making the grand jury's decision unsurprising.
Some people have doubted Wilson's account because Brown's actions (as related by Wilson) seem unlikely based on their experience of typical human behavior. This objection basically makes no sense. Getting shot by a cop is an unusual event and there is no reason to expect that the typical behavior of people about to get shot by a cop is similar to the typical behavior of people in general. Particularly in this case as we know Brown was actually acting abnormally shortly before the shooting when he robbed the store.
The prosecutor also acted abnormally by presenting the case to the grand jury without a recommendation. It seems clear he did this because he didn't want to indict Wilson as if he had wanted to indict Wilson it is hard to see why he wouldn't have proceeded in the usual way. The usual way being for the prosecutor to investigate the case, decide what charges he wants to bring and then present enough evidence to the grand jury to establish probable cause to bring these charges. Probable cause basically means it that is more likely than not that the accused is guilty. Since prosecutors generally don't want to bring charges that they don't think they can prove beyond a reasonable doubt at trial (and because grand jury decisions to indict don't have to be unanimous) it is rare for grand juries to reject the prosecutor's recommendation and refuse to indict. By proceeding as he did the prosecutor risked having the grand jury unexpectedly bring charges leaving him in the awkward position of having to prosecute a case he didn't believe should have been brought but as a practical matter that was unlikely to happen.
I have seen suggestions that in cases like this the prosecutor should obtain an indictment whenever they can and let the trial jury decide the case. In my view this is dangerous nonsense. It seems obvious that it is completely unethical for a prosecutor to attempt to convict a person the prosecutor believes to be innocent. So at least probable cause (in the prosecutor's view) is required. Further in my opinion a prosecutor should not pursue cases in which they have reasonable doubt regarding guilt. And of course a prosecutor has discretion to refuse to bring any case.
That Wilson's actions were not criminal does not imply they were beyond reproach. Opinions about politicized cases like this tend to become polarized leading to the "fallacy of the excluded middle" in which intermediate possibilities are ignored. So for example a police shooting may be neither criminal nor a "good" shoot. In my opinion criminal sanctions for police shootings are only appropriate for really egregious cases which this does not appear to be. Attempting to impose criminal sanctions in borderline cases may even be counterproductive if it leads to police departments focusing on keeping their officers out of jail when police shootings occur rather than on reducing the number of police shootings.
According to this 2011 NYT article police shootings in New York City have dropped drastically in the last forty years.
The 33 instances in which an officer intentionally shot at a suspect last year represented a 30 percent decrease from the year before. But it reflected a far greater drop since the department began keeping these records in 1971, a year in which the police in New York City fatally shot 93 people and injured 221 others.
Last year, the police shot and killed 8 people and injured 16.
So it is possible to reduce police shooting without (so far as I know) sending a lot of officers to jail. The article is based on the New York Police Department's (NYPD) annual firearms discharge report. I suspect that just compiling this report annually by itself encouraged a reduction in police shootings. (NYPD shootings have increased a bit since 2010 but remain way below the levels of 40 years ago).
In general mild sanctions widely imposed are a more effective means of altering behavior than harsh sanctions which are rarely imposed. But of course harsh sanctions often have more political appeal.