Should criminals who commit horrific crimes (sex abuse, serial killer, etc) need to be provided justification of having a mental illness in order for the public to understand how anyone can perform such horrendous acts?
I don't believe all criminals have mental illness only that they intentionally choose to break the law and harm others and are suffering the consequences of their actions. When saying "he had a mental illness" to justify the intent it's almost as if the public is getting the criminal off the hook.
While some criminals do have mental illnesses, this is focusing on those who intentionally commit crimes and are in jail (or so have you-edit-without mental illnesses).
If I'm understanding the OP correctly, I think you're talking about a view I've seen espoused here on RF once or twice. Namely that to commit horrific crimes, you must be mentally ill.
It's not accurate, in any way shape or form that I can understand. Some criminals obviously do have mental illness, just as some non-criminals do. But to take a lack of understanding of criminal motivations and attribute it to mentall illness doesn't really bear up to scrutiny. (ie. I could never commit such a crime...therefore these people are different to me...therefore they are mentally ill)
I do also wonder how many people automatically think of mental illness when looking at victims of crime. Mentally ill people are approximately 3 times more likely than others to be victims of crime (I'm obviously broad-brushing here) for a whole range of reasons.
Apart from the somewhat normal human behaviour of dehumanising those who are different to ourselves (criminals for most of us, and the mentally ill for a somewhat smaller group of us) it's worth considering;
1) Mentally ill in terms of crime refers to people who are ill
at the time of committing an offence. The mental state of a mentally ill individual is not unchanging.
2) Mentally ill in terms of crime refers to the capacity of an individual to understand right from wrong (in simple terms). In NSW, the wording of this is that a jury can find an 'act proven but not criminally responsible' if '
The impairment had the effect that the person did not know the nature and quality of the act; or that it was wrong because the person could not reason with a moderate degree of sense and composure about whether the act was wrong.’ My father-in-law suffers from depression, but is treated for this, and whilst it causes some hardship, and can certainly be classed as a mental illness, it's not going to be an adequate defence for him if he ends up charged with murder one day.
3) People who are found to be physically responsible, but not mentally capable are not found 'innocent by way of insanity' as common thought often suggests. Instead they are sentenced to a long-term supervision order which will include incarceration in a mental health facility on a non-volunteer basis for a considerable time. Even after release (which is generally staged, and takes considerable effort to get to) they will continue to be heavily supervised, quite possibly for the rest of their lives. Obviously this varies in different jurisdictions.
Explainer: The mental impairment defence in homicide cases - ABC News