What on earth is it all about?

I mean, this man had a gun and had tried to kill people including a police officer (not sure whether he managed to actually kill) so he was a threat to the public .... And when police finally found him, he put his gun to his head .... So police instinctly shot him with a taser (licenced or not ..... Who cares) and it didn't work so he killed himself ....

Now what I wanna know .... (and I don't mean this question in a way that is meant to offend or w/e) .... is why are they looking into whether or not the tasers fired had an effect as to him killing himself?
He was a threat and people would have been angrier if he was caught and just sent to jail .... So why? Why does it matter and why is it such a huge deal on the news?
Oh and if it does matter .... What will happen to the police officers that fired?
@OneDrop .... I knew they had a stand off for a long time ... The instinct was that he had moved (according to BBC news) and officers instictly fired ....

I can completely understand that the family deserve to know how it happened, and that they aren't to blame but it should be kept between them and not made a huge thing of

I can understand a little better now about why the inquest is going on, I just wish they would stop making a huge deal out of it .... They seem to just repeat everything over and over ....

And now that you've mentioned it, the guns should be looked into .... But I'm hoping that the officers do not have anything to worry about like court cases about man slaughter or something ... Because they were only doing their job ...