If a person commits a murder, their victim is still dead even if a mental condition is present in the criminal. And I think sometimes people try to use mental conditions as a means to excuse unacceptable behavior. I'm not saying some mental conditions are not serious, but I think they are used as an excuse too often.

in my opinion most severe criminal acts such as homicide or anything along the molestation lines could not be committed without some level of mental instability & on that ground i fail to see how such a crime could go unpunished.
However should it appear that the person could actually be helped to some degree mentally speaking then they should be (within a secure & contained environment & in correspondence with the sentence)

Well it should be taken into consideration, but I wouldn't say absolve completely...

What Jillywinkles said: I think it can be appropriate for some medical diagnoses to result in a commutation of a sentence, but not absolution. That is to say, the sentence may be altered when considering some mental illness, but not removed or avoided altogether, as "absolved" suggests.

As satre once said: if u don't remember commiting the crime you are therefore no longer the same person as the person who commited the crime and therefore cannot be held responsible for it.
this is becaus ehe belives the notion of the 'self' to based on memory, although he does recognise the pratic problems that arise from this philosophy, I think on the whole it's not a bad start.

I don't think absolve is the right word to use. Yes, their mental condition should be taken into account, however they still committed the crime and have the potential to do it again *because* of their mental instability. Insanity plea and rehabilitation in a mental institution is a suitable consequence. When I think "absolve", I think walk out of the courtroom and continue with life.