I am a student of law and presently working on the comparative study of murder and homicide law in Islam and in the Western legal tradition. While doing research on the topic of honour killings I came across with the various judgments of Pakistani courts and of other Islamic countries courts wherein the judges viewed such killings as justified for various reasons:
1. the adulterous is otherwise liable to be punished with death,
2. the murder is committed because of ghairat and the prophet (pbh) has asked people to defend their ghariat,
3.murder is committed because of IZTARAR
4. the person who commits adultery becomes ghair Masoom-ud-dam
5. the killing is done in the discharge of duty which rests upon every Muslim to eliminate evil in possible ways.
These are the five main contentions with some more flimsy reason/grounds they consider while dealing with such murderers with indulgence. I have some very serious objections on all of their arguments. Firstly, Nobody in Islam is allowed to take law in his own hands. Secondly, if the people committing adultery are murdered how the murderer would prove that they were committing such an act which was liable for the death penalty. Thirdly, in saying this he should have brought the evidence which is required to prove the offence of zina - four witnesses who had seen the commission of the sexual acts. Fourthly, no individual can declare another individual a gair Masum-ud-dam. Fifthly, the obligation to eliminate the evil cannot be extended to an extent wherein the wrongdoer may be killed.
There is a lot which my research suggests but I would like to take benefit of your opinion before concluding my research on this topic. I shall be very grateful if you could explain the issue with reference to some primary sources of Islamic law.
Since I have not read any verdicts on honour killings in Pakistan or elsewhere I would comment on the issue in the light of the information you have passed on to me. We do not think that someone who has taken the life of another soul can be let walk free on the given grounds.
We believe that in simple cases of fornication/adultery and rape the victor could be sentenced to death. The Holy Qur'an clearly prescribes flogging the convicted culprits. For detail please refer to: The Punishment For Zina (Fornication) , The Penal Law of Islam
In the light of the above we can conclude that no individuals or state can kill such culprits on the basis of the reasons 1, 4 and 5 given above. As for killing others under the passions of Ghairat we do not think that it is again possible for one to kill on this ground. The Holy Prophet (sws) is reported to have strictly warned people from being driven by the passion and killing something this way. He repeatedly told his companions to turn to the court in such cases and keep away from taking the law in their hands. No moral or legal code permits this in ordinary circumstances. I do not understand what does the word iztiraar connote in this context. May be someone should feel compelled in such circumstances but I don't think that people would agree on this being termed as iztiraar. I can understand that someone is being raped and they try to defend themselves and thus in this struggle kill the offender but I cannot understand that if a person finds someone has committed this heinous act and you feel compelled to kill them.
I think that all the reasons forwarded to justify such killings cannot be expected valid in absence of other facts, which render the act condonable.