The Ruling on Killing a Muslim and the Effect of Repentance on His Sin

Question:
Honorable Shaykh, if a Muslim kills someone and the hudud (fixed Qur'anic punishments) are carried out against him, does that expiate his sin, meaning the sin of killing, even if the killer did not call upon Allah for repentance?

Answer:
If he did not repent, he is under Allah’s will. As for repentance, there is no doubt that Allah accepts repentance from His servants, even from the disbeliever and the one who associates partners with Allah; if he repents, Allah turns to him in mercy. But if he dies without repenting from the killing, is he under the will of Allah like the other major sinners, such that Allah may punish him or forgive Him, or is it necessary that He punish him? This is the basis of the disagreement between the majority and Ibn Abbas. Ibn Abbas says that Allah must punish him, while the majority says he is under the will of Allah like the other monotheists, such that Allah may punish him or forgive Him. As for repentance, since Allah accepts repentance even from disbelief and shirk (associating partners with Allah).