Probably stating the obvious - but we are all armchair experts on this one, sat safe in our homes, offices, or somewhere safe on our chose smart device; viewing the videos with a safe and critical eye.
Personally - do I believe that the Police murdered/executed the guy? No. Though I base that on the same videos we have all seen so far - but I also base this on having faith in our Police officers and their training. The video does look pretty rough though, but the guy clearly makes a move - and who knows what he had on him? A bomb vest, a grenade, maybe a gun... and in the heat of the moment, there is probably no time to be issuing warnings and pleas - maybe the armed Coppers around these key places have even been given an unofficial 'shoot on site' waiver?
Here's hoping that the victims are going to be fine, that no other nutters try to carry out more attacks, and that the guy who was shot deserved it.