I entirely agree with the idea that there are persons that society needs to defend itself from. It’s the same as a physical body needing to defend itself against disease. But if we take an evidence-based approach, our way of addressing the problems would shift. If we know that maternal malnutrition and severe social stresses causes hypertrophy of the amygdala of the fetus, we could cut the crime rate by fixing that part of the problem. The concentration would be on prevention first and treatment second. The treatment would probably include things like psychotherapy or medication.

Again, I think that the example of a person who has their first epileptic seizure while driving. They will lose their ability to control the vehicle, and muscle spasms may cause them to floor the accelerator. If that person were to then plow onto the sidewalk and kill a child, we would not consider that to be a murder. We wouldn’t think it was a deliberate, and we wouldn’t treat them by exorcism because they’re possessed by a demon. We also wouldn’t treat them by locking them alone in a room for five years and then let them go. We would put them on medication, we would teach them coping mechanisms and give them training and therapy for mitigation, and we would pull their driver’s license until we could determine that their medical condition no longer was likely to produce a similar harmful event.

We know that punishment based models do not work. The US has a stunningly high incarceration rate and a level of barbarism in prisons that’s pretty unique among developed countries, but nevertheless has higher recidivism and crime rates than, say, the Scandinavian countries.