Is there an obligation of retaliation (Qisas) if a partner kills his co-owner before becoming aware of the co-owner's pardon?
Chapter on Retaliation (Qawad)
Al-Mughni
Book of Wounds
Primary text
If the partner kills the co-owner before learning of the pardon, no retaliation (Qisas) is due upon the killer. This is the position of Abu Hanifa. The justification is that the killer acted while believing his right to execute still existed. Since the default state is the continued existence of the victim, no Qisas is levied, analogous to a representative (wakil) who kills after the principal has pardoned, but before the representative learns of the pardon. This ruling applies whether a judge had previously ruled on the pardon or not, as the mitigating circumstance (shubha) exists when knowledge is absent and is eliminated when knowledge is present.
Supporting text
A differing opinion from Al-Shafi'i states that Qisas is obligatory because the killing was intentional aggression against someone whose execution the killer had no right to carry out. Furthermore, Al-Shafi'i holds that if the killer commits the act after a judge has ruled on the pardon, Qisas is due whether the killer knew of the pardon or not, distinguishing this scenario from the ruling when knowledge is absent.