1. In addition to the fact that the death penalty is required by Deuteronomy for some offences.
2. This, of course, shifts the crux of the debate to how we know the true God; this, however, is not an issue that Deuteronomy sees necessary to enter into in any sustained sort of way. On the significance of "killing in the name of God," especially in the light of the war on terrorism, see the stimulating article by William T. Cavanaugh, "Killing in the Name of God," in I Am the Lord Your God: Christian Reflections on the Ten Commandments, ed. By C. E. Braaten & C. R. Seitz (Grand Rapids: Eerdmans, 2005) 127-147. The only other alternative to killing in God's name is to kill in the name of one's nation which, as Cavanaugh points out, is really idolatry.