Oomis: There is no reference to Torah in your comment. Torah ought to guide us on the question of capital punishment.
As for your proposal to defile bodies of Muslim terrorists: consider what effect, if any, Arab defilement of Israeli soldiers has had on the IDF, the settlers, and the Israeli population. If anything, it has inspired all these groups to strengthen their resolve to remain in Israel (state, or E’Y, as applicable). So your behavioral approach to the death penalty question is flawed, and your Torah approach is missing or unstated.