Are you also excluding situations like war
Or armed police who shoot a guy before that guy can shoot the hostage? People who are trained in the use of weapons, and where killing someone arguably falls within what's expected of their job (ok, armed police aren't expected to always kill, but you know what I mean).
I hope you don't find my ignorant questioning irritating, I do find this quite fascinating, and like to devil's advocate and hypothesise on these sorts of things.
( Labia Majora You keep on talking but it makes no sense at all, Tue 17 Aug 2010, 12:06, 1 reply, 16 years ago)

"I'm excluding circumstances where the law would offer a separate defence like being bonkers or killing in self-defence."
In each of those circumstances the law offers a defence to that killing.

See also: turning off a life-support machine or performing surgery to separate a parasitic conjoined twin.
( WormuIus, Tue 17 Aug 2010, 12:08, Reply)

Thought as much, but wanted to clarify
Still thinking...
( Labia Majora You keep on talking but it makes no sense at all, Tue 17 Aug 2010, 12:15, Reply)