sunny-dave - "I have every sympathy for people with mental health issues - but some actions are just so far removed from civilised behaviour that no amount of 'making allowances' will excuse them."
No-one is suggesting that making allowances is an appropriate response. What I am saying is that mental illness can and does cause people to behave in a way that the rest of society finds morally repugnant, but that is because of their mental illness, and should not be confused with simple wanton cruelty for its own sake. No-one would say - 'You are mentally ill, so we won't bother about what you did ...', but hopefully would say 'You are mentally ill and need treatment and support'.
"This was a barbaric act, carried out on a defenceless creature - I just can't accept the playing of the mental health defence as a "get out of jail free card"."
As i said, no-one should suggest that this action is excused by mental illness, but it is explained by it. I don't believe that anyone who has direct experience of mental illness would agree with it as a 'get out of jail free' card - that is somewhat adrift of the causes and effects of what mental illness is about.
"Nor does "what good does prison do for women" cut much ice with me - the sentence is a punishment - it needed to be significantly longer."
The concept of punishment is only valid if the action demands it, and the perpatrator understands the concept of punishment, and that punishment is going to deter them in the future.
I believe none of those provisos are in place here - this woman is unlikely to understand the notion of punishment, or indeed of wrong-doing - it is possible that her mental condition puts the comprehension of such concepts out of her reach - but that is for professionals to assess and advise.
I would simply say that we should not jump to conclusions based on the tragedy of the action - but should be willing to accept that tragedy of illness that has helped to cause it.