I've never quite understood the position of those who think that killing people is a good method to illustrate to others that killing people is bad. Also, from a purely practical standpoint, it's rather expensive to put someone to death. It drains much more on the wallet of the tax-payer than simply locking them away for the rest of their lives. Escapes from high-security facilities are extremely rare in this day and age and there isn't really any good chance of a bomber or serial killer breaking loose and wreaking havoc on society again. There's just no need for the death penalty any longer, and frankly, I think the entire principle is stupid.
Yes we need to do this already.
1) If we run our justice system on a desire for vengeance and on often irrational emotional desires, it becomes much easier to make mistakes
2) Nothing can ever be certain enough to end a life, and in this country we have killed an incredibly high amount of people who have turned up innocent
3) The system is unusable in a society that still has prejudice and inequality. Minorities are actually statistically more likely to be given the death penalty when they comment the same crime as a white person. Also if someone is able to afford a better lawyer, they have a better chance than a person who is assigned a lawyer by the court, one who may not even want the case.
4) It has been proven that the death penalty is not an effective deterrent against violent crime
5) Putting a person on death row is actually more expansive than giving them life in prison
6) its downright barbaric and unethical to have state sanctioned killing
I would like to bring up something Gandalf says to Frodo in 'The Fellowship of the Ring' (and I am sure this is not the actual wording, but the idea is accurate): "Many who deserve to die, live. And many who deserve to live, die. Can you give life to those who die unjustly? Then do not be so quick to give death to those who live unjustly." Gandalf is basically saying that killing a murderer is only just if you can give life back to his/her victim. As we cannot give life back to the victims, killing that person is not justifiable.
Also, what of the innocently convicted? If somebody is convicted of murder and killed by death penalty even though that person is actually innocent, there is no way of taking away that penalty, while somebody incarcerated for life may still be taken out of prison and receive compensation. Incarceration leaves its marks, but it is not completely irreversible.
Finally, maybe life without parole is actually worse than death sentence. Personally, I would rather be killed and have it over with than be kept in a prison for the rest of my life, having to deal with the guilt, and even if there is no guilt (psychopathy) having to vegetate in my cell with probably nothing to do, maybe even in solitary, and Kenneth E. Hartman (who is on life without parole) seems to think so too (http://deathpenalty.Procon.Org/view.Answers.Php?QuestionID=001017). Therefore I would support the outlawing of the death penalty.
The number of innocent people that have been killed is astounding worldwide. The U.S. alone Had more than 100,000 people on death row before the Innocent Project exonerated them. I also don't think the government should decide who lives and who dies. Such as thing is too much like 1984.
The death penalty is wrong In many ways. First, the death penalty increases disrespect for human life, and creates the tragic illusion that we can teach that killing is wrong by killing. Second, life in prison is actually less expensive than the death penalty. Also, if One has commited a serious crime, and realizes it, wouldn't they rather die than dwell on their actions in prison? This makes death favorable and preferred. By having those criminals imprisoned for life, it is actually more effective than killing.
If we abolish capital punishment, we would need to maintain life without parole. In my opinion, the death penalty has a few advantages over life without parole. For one thing, opponents of the death penalty are arguing that it is less costly to keep someone imprisoned until they die, but I think it is the opposite. To keep someone in prison for the remainder of their natural lives means taxpayers must keeping paying to feed them three times a day. And it seems like if you are going to sentence someone to die in prison, why not just put them to death?
Yes, most criminals might repent, but most murderers (particularly serial killers) have no remorse for their actions.  They either don't understand or don't care that they have ended someone else's life, and in all likelihood would commit murder again if given the chance. This would lead to them being locked up for life and tried for death. Most people would prefer life in prison as opposed to death in any situation. And if someone truly regretted their actions, they would plead guilty and receive a lesser sentence or a chance of parole in any case.
While it is true that capital punishment costs considerably more than life imprisonment , it's not as though every murderer is being tried for death. Capital punishment is reserved for the worst cases--the ones where numerous victims were involved, especially if those victims were brutalized. But that aside, death penalty doesn't have to cost so much--a hanging or beheading does the job just as well, and is very cost efficient.
A life for a life, is all I have left to say in the matter.
You will always risk a criminal getting out of prison and they could also start a gang type deal when they are released and could lead to more crimes. Also if they would kill more people it would scare many criminals and could lead to less crime.
Think about serial killers / mass murderers. Some do not feel remorse about their actions.
When they're out (If they're allowed out), they'l do the same thing to satisfy their lust. Some might suicide anyways in order to get out of going to prison.
Besides, no matter how secure you think the prison may be, there's always going to be a way to escape. It may take years of shared thinking, planning, etc.
There's always the chance there will be really, really bad, heinous crimes committed.
Whether the death penalty is justified depends on whether the state has educated him/her with proper moral values beforehand. If a ruler executes a citizen without having taught him/her morals, that is murder. 'Sir, in carrying on your government, why should you use killing at all? Let your evinced desires be for what is good, and the people will be good.' (Analects 12.19)
If a citizen has been educated with the proper values, but still performs heinous acts like mass murder, he/she is incorrigible, and should receive the death penalty. This kind of people are extremely rare, but they exist and need to be dealt with. I'd rather keep the death penalty and use it once a century than not be able to use it when called for. 'In "The Announcement to Kang" it is said, "When men kill others, and roll over their bodies to take their property, being reckless and fearless of death, among all the people there are none but detest them" - thus, such characters are to be put to death, without waiting to give them warning.' (Mencius 10.4)