Is the repentance of a murderer accepted, even though Allah accepts a servant's repentance for all sins against Him? And is murder a sin against Allah or against His servants?

The majority of jurists hold that a deliberate, unjust murderer can repent, citing Allah's saying: "And those who do not invoke with Allah another deity or kill the soul which Allah has forbidden [to be killed], except by right, and do not commit unlawful sexual intercourse. And whoever does that will meet a penalty. Multiplied for him will be the punishment on the Day of Resurrection, and he will abide therein humiliated - except for those who repent, believe and do righteous deeds. For them Allah will change their evil deeds into good ones. And ever is Allah Forgiving and Merciful." As for Allah's saying: "But whoever kills a believer intentionally - his recompense is Hell, wherein he will abide eternally, and Allah has become angry with him and has cursed him and has prepared for him a great punishment," this is understood to apply to one who does not repent.

Regarding murder, there are three rights: the right of Allah, the right of the slain, and the right of the slain's guardians. The right of Allah is waived through repentance. The right of the guardian is waived through retaliation, reconciliation, or forgiveness. The right of the slain remains, for which Allah will compensate him on the Day of Resurrection.