Nothing can bring back the soul but no-one has the right to take a soul- there must be repercussions for doing so.
I have always understood 'compensation' for killing another soul only applies for accidental death, a mistake, something not pre-meditated, and 'an eye for an eye' for murder which is pre-meditated, thought out.
Can there be justice for the dead if the murderer is alive?
A Christian priest once said on national TV that the Bible says in the 10 commandments do not kill, so he was against the death sentence for any crime including murder. But in his Bible it says later on what to do to a murderer-kill them! I am not using the Bible to justify my stance, but showing how selective reading can be used to justify any belief; we must look at the whole picture . As the Qur'an prescribes an eye for an eye with alternative punishments for what type of crime is committed, then I cannot say that taking the life of a murderer is anything other than a justified act.
PS- the killing of an innocent life is like killing the whole of humanity so any death sentence for a murderer must be based on 100% proof.