From the link icecab brought:Besides it's not cheap, putting someone to death.
The death penalty is "expensive" in the U.S. only because of America`s judicial system, which allows endless expensive appeals to proceed forever. Israel has no jury system at all.
He will still live. Israeli prisons are not summer camps AFAIK, but it's still possible to live there relatively well, considering the environment. Hey, Samir Kuntar, lebanese terrorist who, among other things, killed a little girl by smashing her head with a rifle in 1979 in nothern Israeli town Nahariya, got a bachelor's degree from an Open University while being in prison.Why should he die a quick and relatively painless death instead of living in a cage?
But yeah, since modern methods of execution are quick and mostly painless, the death sentence will be an easy solution for him. I can think of some medieval methods of execution that fit his crime, but they are not used since like 18th century.