Likewise, a fully-owned slave (qinn), a mudabbar (a slave set free at the master’s death), a mukatab (contract slave), and an umm walad (a slave-woman who has borne her master a child) are executed for killing one another. If a slave kills another slave and is then manumitted—or if the manumission falls between the wounding and the death—the case is treated just like a killer who embraces Islam after the crime: the retaliation is not waived.

A person who is partly free is, in the default view, not executed for killing another who is partly free; a second opinion says he is, provided the killer’s share of freedom is not greater than the victim’s. No qiṣāṣ is carried out between a Muslim slave and a free dhimmī. Nor is retaliation taken when a parent kills a descendant, however remote, nor on that descendant’s behalf; yet a child is executed for killing either of his parents. If both parents lay claim to a foundling and one of them kills him, then, should a qualified physiognomist (qāʾif) later attribute the child to the other claimant, retaliation is taken; otherwise it is not.

If two brothers kill their parents in such a way that one slays the father and the other the mother at the same time, retaliation is due for each killing and the order of execution is decided by lot. Once the lot has been drawn—or if one of them is executed first of his own accord—the second is also put to death, so long as the estate of the first does not thereby devolve upon an heir who is barred because of lawful homicide. The same ruling applies when the murders occur successively and no marital tie complicates the inheritance; if such a tie exists, only the second killer is executed.

When several people jointly kill one person, they are all put to death for him. The heir may pardon some of them in exchange for each killer’s proportional share of the diyah, reckoned per head. A partner in an accidental or quasi-intentional killing is not executed, but the following accomplices are:
• the associate of a father who kills his child;
• a slave who helps a free man kill a slave;
• a dhimmī who helps a Muslim kill a dhimmī;
• the accomplice of an enemy combatant;
• the accomplice of a highway robber whose crime entails either qiṣāṣ or a ḥadd;
• any accomplice in deliberate homicide (sharīk al-nafs); and—according to the sounder view—one who oversteps the bounds while repelling an unlawful aggressor.

If a man inflicts two wounds, one deliberate and the other accidental, and the victim dies from their combined effect, he is not executed. The same applies when he wounds an enemy combatant or an apostate, that person then embraces Islam, and he wounds him again so that he dies.

Should the victim treat his wound with a lethal poison, the original assailant is not executed. If the poison is not normally fatal, the case is classed as quasi-intentional; if it is ordinarily fatal and the assailant knew that, he is counted a partner in the victim’s self-killing—though another opinion says he is a partner in accidental homicide.

If several people whip a man until he dies, with each individual stroke being non-lethal on its own, there are three views concerning qiṣāṣ; the soundest is that they are executed, provided they had conspired together.

Whoever kills several people in succession is executed for the first victim only; if he kills them simultaneously, the one for whom retaliation is taken is chosen by lot and the heirs of the others receive diyahs.

I add: if someone other than the first victim is avenged, the executor has sinned, the retaliation nevertheless stands, and the heirs of the first victim are entitled to the diyah. Allah knows best.