Robert Blecker of New York Law School (one of the very few academics who supports the death penalty) has this article in City Journal on an alternative for those states that have unwisely abolished:
For 25 years, doing research, I've spent thousands of hours inside maximum-security prisons in seven states. What I've seen has appalled me. Convicted murderers play softball, volleyball, and Ping-Pong. Vicious men who raped and murdered children watch soap operas on color TVs. Serial killers who tortured their victims to death munch on snacks that they "shopped" for at prison commissaries.
As administered today, prison life completely disconnects crime from punishment. When I began my prison travels in 1986, I assumed that legislatures and corrections departments wanted serious crimes to result in serious punishments. But inside prison, it turns out, it's nobody's job to punish. Consult corrections departments' mission statements: not one so much as mentions punishment. Except for security concerns, every prisoner--whether killer or car thief--enters with a clean slate. Officers speak with one voice: "What a guy did out there is none of my business. How he behaves here is my only concern." Lee Mann, a warden's assistant at the Oklahoma State Penitentiary, summed up best the indiscriminately immoral life in prison: "We want to make the time for them as easy as we can, because it makes it easy for us if it's easy for them."
For retributivists--those who believe that the punishment should fit the crime and that criminals should get what they deserve--the closest thing to the death penalty is not LWOP as it's typically administered, but a special kind of life sentence that I call "permanent punitive segregation," or PPS. A PPS sentence would be as unpleasant as the Constitution allows. PPS inmates would eat nothing but nutraloaf (a tasteless, nutritionally complete patty) and would get no canteen goodies. Visits would be kept to a constitutional minimum, and none would be "contact visits"; that is, these depraved murderers would never again touch another human being. To fulfill their constitutional right to exercise, they would labor daily but never play. They would certainly have no TV or Internet. Photos of their victims would adorn their cells, out of reach but in their faces. Officers assigned to guard PPS prisoners would familiarize themselves with the crime that brought the punishment. Society would tolerate no beatings or sadism from officers, but there would be no conviviality, either.
Good luck with that. I do not expect it will ever happen. For justice in the worst murder cases, we need to keep the death penalty where it exists and restore it where it does not.