Cathedral shooting - Imitation gun?

[DEB4369]

I've just read that the man shot at the cathedral at the end of last month had an imitation gun loaded with blanks (it's the kind that can apparently be altered to fire live ammunition, but it's thought this one wasnt). While I see that it is wrong and dangerous to carry an imitation gun, especially in these times, is it really ok to just shoot and ask questions later. Is it really necessary to shoot to kill when there's uncertainty?
Not so long ago it was the sort of thing you only heard of happening in America and other countries. I suppose it happening closer to home makes it seem like it really is becoming commonplace in this country. The government is working harder and harder to convince young people they do not need to arm themselves against threats, yet the government is also arming its police to shoot and ask questions later it seems.

[spencer]

The police can't win in these situations. If they shoot the person they face all sorts of investigations and criticisms and if the person shoots someone else they are criticised for not preventing it. It's sad, but we now live in a situation where the poloce have to assume the worst and then act - which may mean killing someone if the sitaution looks dangerous.

[Marc Scott]

It is a shame that we do now live with this situation where, as spencer said, either way the police are at fault for some aspect of the situation. Although I was shocked to see on the news about the de Menezes shooting how that they are told without question to deliver a fatal shot to the head.
It's all a bit of a grey area and nobody ever seems to be in the right whatever happens.