Doctors and the death penalty

Would it be permissible for a Catholic physician to administer a lethal injection to a prisoner condemned to die? What if the alternative was a poorly trained prison guard? What if the physician only stepped in if the initial injection did not do the job and the prisoner was suffering? These questions are implicated by a New York Times article today addressing the emerging controversy over the ethical propriety of physicians participating in lethal injections, which are increasingly becoming the preferred mode of capital punishment in this country. In fact, the issue may be complicated somewhat by language in a recent Supreme Court decision suggesting that a physician would need to participate, or at least be present, if the procedure was not to constitute cruel and unusual punishment. Nevertheless, my assumption would be that, unless the imposition of the death penalty in a particular case was justified under Church teaching, the Catholic physician's participation would not be permissible, regardless of the practical difficulties or secondary forms of harm the refusal to participate may cause. If anyone disagrees (or can more coherently buttress my inclination), I'd love to hear from you.

Rob