The argument for exempting persons with severe mental
illness from the death penalty is that the death penalty –
the harshest of punishments – does not deter, serves no retributive
function for, and is a disproportionate punishment
for individuals who are less culpable for their crime than the
average person.
This reminds me of an anecdote told to me by a prison chaplain about a prisoner who had requested pie for his final meal, but left it uneaten in his cell, because he thought he would be coming back to finish it later. If the person lacks even the understanding to know, after years of preparation, that what is about to happen to them is final, how could they possibly be expected to realize prior to committing a crime that they might be executed for it?
At this point sometimes unfortunate arguments begin to appear about how "putting down" people who lack moral understanding is good for society whether they understand what's happening or not--but it is ridiculous to pretend that we lack the ability to keep these people under adequate medical care to prevent them from committing further crimes, and once you begin justifying killing people just because they are inconvenient, you've started down a slippery slope indeed.
The report is a great read, finally listing among its conclusions that:
Everything possible should be done to reform and improve
the mental health system so that individuals with severe
mental illnesses can receive affordable and appropriate treatment
they need, thus preventing, or at least minimizing to a
far greater degree than we now do, the risk of violence committed
by some individuals who experience acute psychotic
symptoms of mental illness.
