As an abstract question in moral philosophy, I think I’m for capital punishment, on two grounds.
First, if we punish petty theft with a little time behind bars and aggravated assault with somewhat more time behind bars, arguably there are some crimes - and I’m not at all sure that homicide is alone - that ought to be punished in some way not reducible to the less-time/more-time dimension, precisely because we want to mark them out as capital - i.e., chief - offenses.
Second, the real suffering created by a relatively humane execution may be much less, integrating over time, than the suffering created by a long prison term, both for the offender and for his intimates, and yet the fear of death appears to be such that most offenders (not all) prefer any non-capital sentence to death. As John Stuart Mill pointed out, the ideal punishment is the one that combines the maximum of terror with the minimum of actual suffering. [That argument would be more persuasive, of course, if the gap between sentence and execution were shorter; even if killing someone is less cruel than locking him in a cage for the rest of his life, forcing him to spend a decade waiting to be killed may not be. The same applies to the suffering of his intimates.]
Moreover, I’m not at all comfortable with life in prison without parole, or even with very long sentences short of that, because I don’t think that the 60-year-old we’re keeping in prison is, in the relevant sense, ‘the same person’ as the 20-year-old who committed that murder forty years ago.
And the risk of executing someone innocent is a strong argument against capital punishment only if death is in fact a much worse penalty than long imprisonment. I’d love to see procedural changes, starting out with much stronger charges to juries about the meaning of ‘proof beyond reasonable doubt,’ to make it less likely that innocent people get convicted, because I’m convinced that the we now have literally tens of thousands of innocents behind bars. But the abolition of the death penalty wouldn’t change that concern at all.
(There is, apparently, evidence to support the common-sense proposition that death-qualified juries — those from which jurors unwilling to convict in capital cases have been excluded — are more conviction-prone than ordinary juries, but that problem could be overcome by having a non-death-qualified jury consider guilt, without being told whether the case is a capital one or not, and a death-qualified jury consider the penalty.)
It’s also more than possible, though not proven, that the threat of execution changes the behavior of some offenders in the right direction. Putting the econometric evidence aside, as I’m inclined to do on topics this complex, there are accounts of bank robbery gangs in the 1930s who went into banks with unloaded weapons precisely to avoid the risk that someone would be killed and the robbers therefore subject to execution. I believe it is also the case that kidnappers-for-ransom of that era were reluctant to kill their victims - otherwise presumably a risk-reducing step - for the same reason.
Of course the opposite effect is also possible: perhaps some people commit crimes precisely so as to be executed, or find that the commission of a capital offense adds to the thrill. The empirical question — or quasi-empirical, if as a practical matter we can’t convincingly disentangle all the evidence — is whether the net effect is positive or negative. (And of course the answer to that might not be the same in all times and places.)
In my moral calculus, saving the lives of victims outweighs saving the lives of aggressors, at least if the numbers are even, and possibly even if they aren’t. The distinction between aggressors and victims seems to me to trump the action/omission argument that it’s not in general justified to cause a death directly in order to prevent a larger number of deaths. The cases used to make that argument tend to involve innocent parties on both sides, which is not the case here.
I recall an essay, though I’ve forgotten the title and author [Can any reader supply?] which makes the general moral case for the practice of criminal punishment on the following argument: If a situation arises in which it necessary that either A or B be injured, and if that situation arises due to the action of A, then it is A who should suffer. Insofar as that argument is valid, it greatly weakens the force of the argument from the act/omission distinction.
All that said, I have no trouble understanding, and sympathizing with, the position of those who regard capital punishment as the last vestige of human sacrifice and are aggrieved at being made complicit in it as taxpayers and voters.
(If I were a Christian, I think I would regard the account of the woman taken in adultery [John 8 1-11] as reflecting a clear judgment against the practice.)
When pro- and anti-death penalty demonstrators shout at one another outside a prison where someone is being killed, I know which group I’d rather go out to a meal with afterwards.
What I’m pretty sure of is that, in purely practical terms, the death penalty doesn’t deserve the attention it gets from either side of the debate. With the annual execution count below 100 and the annual homicide count near 20,000, it seems to me perverse, in a world of limited resources, to worry about abolishing executions rather than preventing murders. But even if it were the case that the death penalty prevented homicide, as a practical matter we could never carry it out frequently enough to make a measurable difference.
From the perspective of a generation ago, with rising crime rates and a scarcity of prison beds, it was not entirely irrational for voters - many of them angry about crime, prepared to be cruel to criminals in order to stop it, and worried that elected and appointed officials might be unduly inclined toward mercy - to use support for the death penalty as a simple test for a candidate’s willingness to be tough. But surely, with 2 million people behind bars, we’ve gotten tough enough.
I am, therefore, indifferent on the question of a moratorium on executions. But as someone professionally concerned with crime control, I’m a strong supporter of a moratorium on debating the subject; it’s a distraction from the work we really need to do.