Solid, would you rather pay tax dollars keeping prisoners alive for their entire lives, or would you rather see them publicly executed for being an infant-eating devilbeast?
Another idea I thought of was a forty strokes less one approach. Nobody likes pain, and if you, say, whip them publicly forty times once a month for a year, unless they are literally insane, they will not do whatever crime. If they murder somebody, maybe they could get forty strokes less one once a month for their entire lives.
Because I can quote a prisoner. He used to be an Irish Terrorist. In an article about what happened to him throughout his life, he even said, "Prison didn't rehabilitate me." Plain and simple.
You have to remember, prison isn't just a punishment, it's supposed to be justice. Life in prison is a punishment that fits the crime, yes, but it is torture. Most people would rather die than go to jail for life, and they do kill themselves. I've seen throughout this that the death penalty doesn't in fact fit most scenarios, but maybe we shouldn't torture them, just make sure it cannot happen again. Ever.
Kill them or Whip them once a month for however many years. Forty strokes, no more, no less.