Reliance of the Traveller, a manual of Islamic law certified by Al-Azhar University, the most respected authority in Sunni Islam, says:
"retaliation is obligatory against anyone who kills a human being purely intentionally and without right."
There you go, and the Muslims and their chirping apologists are absolutely right when they insist honour killing are purely cultural and have nothing to do with Islam.
Hang on, I missed this bit...
"not subject to retaliation, however, is a father or mother (or their fathers or mothers) for killing their offspring, or offspring's offspring." (RoT 1.1-2).
In other words, the killer of their child or grandchild incurs no legal penalty under Islamic (Sharia) law.
It may be that the above have been taken out of context because I would be most surprised if Allah or his peaceloving messenger would agree with such savagery. So I shall dig in and wait for TDs illustrious apologists to respond firmly and immediately and who knows, perhaps even coherently.
Meanwhile:
Iraqi women recently demanded tougher sentences for honour murderers that tend to get off lightly, but this was dismissed by the democratically elected Iraqi government because it contradicts Sharia.
The PA doles out pardons or suspended sentences for honor murders.
Syrias reformed law for increasing sentences for honour murderers (2009) allows a man to benefit from 'extenuating circumstances' in non-lethal crimes of passion or honour, but he should serve a prison term of no less than two years in the case of killing.
Afghan women protested for stronger sentencing for honour murderers, but most of them went home when the culturally inclined men started beating them.
2003 saw the Jordanian Parliament vote against stiffer sentences for honour killers, on Islamic grounds, because Islamists protested such laws violate religious traditions and would destroy families and values.
So there you have it, the Muslim murderer of his own children or grandchildren should be lightly punished if at all, in order to preserve the sanctity of Muslim family values. But there's nothing religious about it.