Who deserves to be hanged by our judicial system? This is an emotive question. And honestly, it's one that I have had trouble answering sometimes. At various times, I have thought that terrorists, people who kill others in hate crimes, and people who kill their parents should be eligible for hanging. After all, limiting hangings to these crimes would make it sufficiently rare, and a fitting punishment for extraordinarily evil acts.
However, there's a catch. Hanging is irreversible, and the judicial system is not perfect. I have done my research, and have found several cases of people found guilty of the above crimes but had their convictions overturned on appeal. If those people were hanged, that would have been a grave injustice.
Hence my conclusion: I can never support the state sponsored execution of criminals, whatever the crime. I firmly believe that there is a special place in hell for terrorists, people who kill others in hate crimes, and people who kill their parents, but it's not the place of our justice system to condemn others to death if it is imperfect.