Countries like Saudi Arabia have a number of capital offenses, some of which seem to extend beyond sharia law; e.g. the list on Wikipedia includes "espionage" and "drug smuggling".
However, I don't know how accurate it is, and I'm unsure if the Saudi government has Islamic justifications for these laws (perhaps they do, and I'm simply unaware). I'm also interested in a situation in an Islamic state, not just how it's implemented in a particular country.
Question: May an Islamic state legislate the death penalty for non-sharia crimes?
By non-sharia crimes, I mean crimes that are not justified Islamically in one way or another.