User6726's answer to this question seemed to imply that an officer's discretion was endless; that no matter what the situation, they could always decide not to intervene. That seems highly unlikely to me; surely if an on-duty, not undercover cop saw for example a stash of illegal weapons in the open trunk of a car, with the criminal sleeping inside it, they would be obligated to act?
My suspicion is this: there isn't really a point where they're no longer allowed to use discretion. More likely, I think they always possess discretion and duty at the same time; they have a duty to stop crime to the best of their power, and they have the discretion to decide whether they're capable of stopping the crime at that point with more benefit than loss. No matter the situation, they technically possess the right to deem the situation too something to not intervene; their duty lies in making that judgement earnestly.
Which is where the practical line between discretion and duty comes in: as said, I think they probably exist at the same time, but certain situations are of a nature that it becomes clear beyond a reasonable doubt that the officer did not exercise their discretion earnestly. In these cases, they would face reprecussions not because they used a discretion that they didn't have, but rather because they clearly violated their duty to use that discretion earnestly. In the kinds of situations where e.g. a criminal is aiming a gun at someone, a cop may decide to not intervene due to their tactical/psychological/whatever judgement of the situation/criminal telling them that intervention would be more likely to cause more harm, and thus I expect a lot of violent situations to fall on the discretion side of this line. So, then the questions arise:
- Does such a line exist, and if so, what does (if anything) the law say about it?
- How is this line evaluated in practice?
I'm interested in the US jurisdiction. Someone mentioned that this depends extremely on the particulars of the situation. I'm more looking for an overview of the categories of situations that are usually treated as an "officer's discretion rules" versus the categories of situations where this isn't the case.
To aid in this, I'd like answers containing constructed scenarios (like my example of the criminal sleeping in his gun-loaded car) where discretion practically doesn't rule (practically doesn't rule in the sense I described above), and constructed scenarios where discretion definitely rules, and lastly, the constructed scenarios where it very much falls in a gray area that needs to be scrutinized due to a high contingency on the particular detials.
Of course, the constructed scenarios could be replaced with real-life cases.