http://www.theage.com.au/victoria/newsagent-killer-didnt-know-what-he-d…
Garry Angus's a well known Victorian newsagent working late in his newsagency was murdered by being stabbed 30 times in October 2011. Interestingly his killer admitted that he had purposely gone to the newsagency to kill Garry Angus.
The court has decided the killer was not guilty of murder by reason of mental impairment.
You can read more at the above link.