In order to stop a potential threat, police inacted a preventative measure that would have only been justifiable action by the state after any crime if he had been found guilty of said serious crime. Interesting arguments to be had in this.
On one side it is the state's duty to protect the lives of it's citizenry, so using any force required to protect the law abiding members has justification. Including shooting down kids waving guns like they are planning on taking shots off.
On the other, there is the aspect that the action of shooting the kid is equivalent of judging him guilty of a crime before he committed it and carried out punishment of said crime.
There is also the aspect of the rise of police powers in contrast to decreasing citizen rights where a citizen in the same situation putting a bullet into the kid would most certainly be arrested and charged even if everything else was the same. Hell, even if the kid had already shot someone, they would likely still have been arrested where the cop is not. Granted, training, weaponry and some privileges are aspects of the job, but I have to wonder if law enforcement are becoming the sole defenders of life, even at the expense of our own rights to defend it ourselves.
As for my thoughts, I do see the killing a justifiable precaution in order to save lives from a potentially very deadly threat, but I still dislike the growing gap in powers the police are gaining above citizens in terms of ability to defend themselves. That is to say nothing of the abuse police can inact with them, as examples of the Wall street protests have shown with mace and other methods on perfectly peaceful, if annoying, protestors. And I could probably make a case about the non-leathal alternatives being used more freely and not only in place of more dangerous methods, but as a tool of their own which is what causes the distrust and fear of them in the first place. If tazers were only used on people who would have been whacked with the baton if they didn't have the tazers, then no one would ***** about them like they do when old women get zapped for raising their voices.