http://www.motherjones.
The link above shows thirteen men that have been condemned to die despite the fact of their mental disabilities.
In Furman v. Georgia, 408 U.S. 238, (1972), the Court invalidated existing death penalty laws because they constituted cruel and unusual punishment in violation of the Eighth Amendment. The Court reasoned that the laws resulted in a disproportionate application of the death penalty, specifically discriminating against the poor and minorities. The Court also reasoned that the existing laws terminated life in exchange for marginal contributions to society.
There's no record of a medical or scientific inquiry into whether this would be the best method, and there isn't any medical evidence to support this approach. Part of the paradox is that it looks like a medical procedure, but it hasn't been rigorously tested. There are no controlled trials, data collection, analysis or peer review of the processes to determine whether it works the way it's been said to work.
Opening Statement:
“If you try to fix violence with violence, you do nothing but create violence.” The death penalty should not be allowed under the eighth amendment. This is due to the death penalty being a type of cruel and unusual punishment.