ok, this may derail from the death penalty allowance.
Allow me to illustrate the invalidity of Shadis's argument further.
Driving, while contributing to greenhouse gases, is completely bifurcated from the concept of terrorism. Driving is accepted by society as a reasonable means of transportation. It's concept is solely based around the transportation of goods or individuals from location to location. In addition, by being part of society, you waive your right to make unilateral decisions about things such as the reasonableness of driving. Instead, you are part of a democratic or communal decision on whether or not driving is permissible. Clearly, since driving is accepted worldwide, it is given that the community accepts driving.
On the other hand, the community does not accept terrorism. Individuals, or individual groups may accept terrorism as a reasonable means to achieve a goal, but the worldwide community clearly does not. One may argue that each individual or individual group forms a select community that permits such behavior, but by attacking an exterior entity, that so-called community joins the worldwide community and forfeits its allowance in favour of the decision of the larger worldwide communal decision.
Anyways, back to death penalty.
Regardless of what a person does, the death penalty is never the answer, if for no other reason than the possibility of killing an innocent person and then discovering the person's innocence a posteriori.
“I hold this position for a number of reasons: these include the fundamental nature of the right to life; the unacceptable risk of executing innocent people by mistake; the absence of proof that the death penalty serves as a deterrent; and what is, to my mind, the inappropriately vengeful character of the sentence.” - UN High Commissioner for Human Rights Navi Pillay
In addition, there are economic reasons for favoring life without parole over the death row.
"The additional cost of confining an inmate to death row, as compared to the maximum security prisons where those sentenced to life without possibility of parole ordinarily serve their sentences, is $90,000 per year per inmate. With California's current death row population of 670, that accounts for $63.3 million annually." - Report of the California Commission on the Fair Administration of Justice (2008)
Finally, the purpose of the prison institution is rehabilitation and not punishment. Every person, regardless of crime, deserves the chance to be rehabilitated. Unfortunately, society's perception of prison is one of punishment, hence the lack of funding to programs designed to rehabilitate.
"Until the mid-1970s, rehabilitation was a key part of U.S. prison policy. Prisoners were encouraged to develop occupational skills and to resolve psychological problems--such as substance abuse or aggression--that might interfere with their reintegration into society. Indeed, many inmates received court sentences that mandated treatment for such problems." - ETIENNE BENSON - APA - Rehabilitate or punish?
"When properly implemented, work programs, education and psychotherapy can ease prisoners' transitions to the free world" - Chris Haney, PhD University of California.