“..the county commission had to authorize a sizeable property tax increase, in order to conduct a death penalty trial.”
I have heard the argument about how expensive it is for all of the retrials and stuff related to death penalty verdicts as well. It is actually cheaper to put them away for life!
In my state, we do both - we pay the expenses for a death penalty trial, and still pay for lifetime imprisonment, because nobody has been executed in 50 years.