Murder is bad because it involves depriving people of a fundamental human right, the right to live. Obviously if everyone took out the people who annoyed them or provided competition for resources, there would be nobody left. Killing people is unnecessary within a modern society because problems can be solved through more peaceful means, respecting the wishes of others.
As to whether people should be given the death penalty for whatever reason IMO we should be practical. Because we can never really be sure of the conditions below, we can not execute people.
There has to be:
A) Absolutely no doubt as to guilty status of the criminal.
and either:
B) No chance of reform for the criminal.
C) A particularly evil crime(s) commited by the criminal.
People make mistakes and new evidence can always emerge that totally disproves the previous verdict. Mental illness, impulsive behavior and accidents are examples of reasons for crimes occurring that we cannot understand. We can never really know what people are thinking and what drives them and therefore cannot predict their future actions, determine if they are 'guilty' and execute them. The ever precent element of doubt and a lack of more information convinces me that we should not decide to kill an alleged criminal.
But to be practical, it is still terrible to take people and put them in prison. But such isolation policies do need to exist to protect society or at least make them feel safe. It is unlikely that the impulsive murderer would strike again but that fact would not be much use to the next victim of terrible crime. I think that if a society can afford to look after people, we should. If it is much too dangerous and costly (and I mean costly by welfare state standards), to keep people in prison then maybe we should whip out the guillotine, but in the Western modern world this situation cannot occur.
I think that a lot of crimes are personal choices, but a fair number of folks are more likely to commit crimes because of their social circumstances. Since we can't really make a good empirical finding about "what causes crime", the question should perhaps be "what are we willing to do about it as a society."
We do need to find the cause of a problem to try to prevent it but we will still always have deal with people who commit serious crimes.
If you interview prisoners on long jail terms you find that most of them are just very stupid and poor. Their social circumstances are instrumental in putting them in such situations. Many would never kill if they lived comfortably in a peaceful environment. Furthermore, should intellectually sub-normal (ISN) people be held accountable for there crimes? The line between ISN individuals and the mentally ill is blurred to the extent that we cannot think we have the right to sentence people to death. More financial/legal equality between classes, a change in mindset (if one can change your own culture) and better education reduce violent crime but are very difficult measures to carry out. Even if this happens, there will always be those accused of murdering their fellow man. So what to do with them? Prison is obviously a poor and inefficient system.
I'm for it, put the criminals on a secluded are, or island, and let them live for theirselves. You take away cruel punishment, for banishment, which I find much better of a system, and if the victim (if there were any) doesn't find this fair, appeal, or go find them and kill them.
Because most of the inmates are poorly educated, ISN and from a violent background of crime, such a system would fail because the class ratio would be unbalanced (like Alpha island from Brave New World) and the society would collapse into violence and anarchy.
However if the above causes of crime were addressed, a slightly more balanced spread of social groups would emerge (equating intelligence with less of a tendency to commit violent crime). Although it would actually take an immense amount of money and aid in the form of a service of councillors, psychologists and of course non-involved security forces, such an exile policy could work. A fairly normal society could exist that would have the full compliment of professions and could contribute to the national economy, or at least recoup the costs, while experiencing a fairly high standard of living. 'Truman show' prisons would have to be graded by crime and would all be self governing as far as the real government would allow. They would behave well as the threat of a spell in the 'old fashioned prison' would be a good deterrent and a comfortable life would make re-offending seem insane. The truly evil people who do not fit into any society can stay in normal prison but can be given a chance to prove their good intentions. A large network or mega city would need to be established to let people have families and not become imbred. People might even be released back into the real world if they gained enough brownie points and one day, the walls of entire isolation suburbs could come down. Will this society be evil, I think not. Stalin's children were not homicidal maniacs and my country of origin used to be a colony of convicts and is now one of the most peaceful and civilised nations in the world.
Do you think this would work?
Revenge is a very powerful force of human nature but we must try to forgive and forget to make the world a better place instead of escalating problems. Wouldn't it be nice if Christian people actually tried to act on their own doctrine and be more like Jesus.