Zeinab  Al-`Alawani, Instructor of Fiqh and Islamic Studies, Graduate School of Islamic and Social Sciences, states the following: “Murder is a serious sin in Islam. It is one of the most repugnant acts to incur the wrath of God. Whether this result is accurate or not, it does not change the fact that each person is responsible for his own action. Whether a serial killer has been used by other people, the fact remains that he is accountable for his deeds. That is why we are advised in Islam to enrich our faith, protect and develop respect for others, share peace, and refrain from any action that might lead us to the haram.
It is true that devils whisper to human beings to commit horrible acts, but as the Qur’an put it, “he does not have control over those who have faith and rely on their Lord.” (An-Nahl: 99) Therefore, the responsibility of the individual is the key here.