Under the same sharia (e.g.: that of Ahmed ibn Naqib al-Misri) that states that honour killing cannot be punished, it states neither can the insane. So this was an obvious plea for a Pakistani from a nation founded by jihad, and founded on sharia.

A man who stabbed his wife and daughter to death in their West Auckland home spent the next seven months trying to dupe health professionals into thinking he was insane.
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Malik was observed among other prisoners, while on remand, acting normally but as soon as he came before a psychologist, he changed. He told doctors he had no memory of his age, name or his family but all agreed there was a strong element of faking.

Killer tried to dupe health professionals into thinking he was insane