Whether repentance of killer is accepted
7-4-2016 | IslamWeb
Question:
Assalaamu alaykum. How can we relate these three reports? The famous hadith of Ibn ʻAbbaas saying that killing a muslim can not be forgiven, a hadith from him saying to a person who killed someone, “Are you parents alive,” and then stating, “I do not know of any act that can wipe out sins like being good to ones parents,” and the hadith that is good according to Al-Albaani that says that Ibn ʻAbbaas said that that the killer is not forgiven unless he repents.
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ʻalayhi wa sallam, is His slave and Messenger.
There are two famous views reported on the authority of Ibn ʻAbbaas 
regarding the repentance of the killer; one is that his repentance is accepted, and the other is that his repentance is not accepted.
The reconciliation between these two reported views was mentioned by several scholars. For instance, Shaykh Ibn ʻUthaymeen 
said:
“If it is asked, ‘What is your opinion regarding the authentically reported view of Ibn ʻAbbaas that there is no repentance for the killer?’ There are two possible explanations: The first is that Ibn ʻAbbaas believed that it is quite unlikely that the repentance of the killer who intentionally commits murder will be accepted, and that he will not be guided by Allaah to repent and accordingly his sin will not be waived and he will be punished for his crime.
The second possible explanation is that Ibn ʻAbbaas meant that there is no repentance for such a killer as far as the right of the victim is concerned because the killer who intentionally murders a person is liable for three rights: the right of Allaah, the right of the victim, and the right of the guardians of the victim (blood heirs).
1- As for the right of Allaah, there is no doubt that (sincere) repentance is sufficient regarding clearing oneself of one's liability from the right of Allaah. Allaah says (what means): {Say: O My servants who have transgressed against themselves (by sinning), do not despair of the mercy of Allaah. Indeed, Allaah forgives all sins...} [Quran 39:53]
This is for the repentant.
2- The right of the murdered person's guardians (blood heirs): it is waived when the killer surrenders to them and confesses his crime saying, 'I have intentionally killed so-and-so; do whatever you want to do with me!' They have the right to kill him in retaliation, accept the diyah (blood money), or pardon him.
3- The right of the killed person (victim): there is no way for someone to clear himself of his liability for this right in the worldly life.
Hence, the view of Ibn ʻAbbaas saying that there is no repentance for the killer could be interpreted to mean that it is not accepted as far as the right of the victim is concerned.
However, the preponderant view to me is that if such a killer turns to Allaah in sincere repentance, then even the right of the victim is waived. It is not that his right will be lost; rather, Allaah relieves the repentant (killer) from this burden and fulfills the right of the victim Himself, rewarding him with elevating his rank in Paradise or pardoning his sins. That is because sincere repentance cancels out all sins; this is supported with the general indication of the verse: {And those who do not invoke with Allaah another deity or kill the soul which Allaah has forbidden [to be killed], except by right, and do not commit unlawful sexual intercourse. And whoever should do that will meet a penalty. Multiplied for him is the punishment on the Day of Resurrection, and he will abide therein humiliated - except for those who repent, believe and do righteous work. For them Allaah will replace their evil deeds with good. And ever is Allaah Forgiving and Merciful.} [Quran 25:68-70]” [Majmoo' Al-Fataawa]
For more benefit, please refer to fatwa 87847.
Allaah knows best.