I can't understand the mentality of holdnose at all.
I personally have some sympathy for all criminals, including the attacker here, for I am quite sure he was a man with complex issues and was vulnerable and someone, somewhere, took advantage and brainwashed him. Which is really sad.
HOWEVER
This man killed two people, injured others and as far as police were aware, appeared to be about a detonate an explosive device which would have killed countless more people.
How was there ever any other option of killing him?
There wasn't.
He had to die.
There was absolutely no way he could have been safely detained without risking the death of very many more innocent people and to call the officer involved a 'murderer', is just reprehensible.