The Moussaoui case raises two issues.
The first is whether the death penalty is the appropriate verdict in this case, given existing federal law. I take no stand on this issue, since I have not heard all the facts of the case.
The second issue is whether the death penalty is good policy. My answer is no.
To begin, mountains of social science evidence have failed to uncover a substantial deterrent effect of the death penalty. Moreover, common sense suggests that absent execution rates far higher than those observed in modern economies, no criminal should reasonably fear the death penalty. There are fewer than 100 executions per year in the US compared to roughly 16,000 murders.
Beyond failing to reduce murder, the death penalty prevents the criminal justice system from correcting mistakes. The number of people falsely convicted of capital crimes is probably small, but it is unlikely to be zero. Everyone benefits if such cases are partially remedied by freeing those found innocent post conviction.
In addition, the death penalty crowds out discussion of policy changes that might actually reduce crime. I will argue in a later blog that drug legalization is the best example of such a policy.
Use of the death penalty does have one potential benefit, which is saving the resources required to incarcerate someone for life. The net reduction in government expenditure, however, is likely small or even negative given that death penalty cases involve protracted penalty phases and lengthy appeals. The penalty phase of the Moussaoui trial would be trivial if the death penalty were not an option, but it is expected to last one to three months because of the prosecution’s request for the death penalty.
Putting Moussaoui to death might seem appropriate to many people, and this is understandable given the horror of the 9/11 attacks. The broader question, however, is whether the death penalty is an effective criminal justice policy. The answer appears to be no.