Jim,
God did not set up capital punishment no more than He set up slavery. Both laws, no, all three, divorce, slavery, and capital punishment were set up to control what man had already invented for themselves. I have done an extensive study on this due to my chats with the atheists. Try explaining how a loving God can order men, women, children, and even animals to be killed. Slavery, CP, and divorce are easy in comparison.
BTW, if anyone is interested, the explanation of how God can order a nation down to every living creature killed can be found under The Laws of Warfare in Deuteronomy 20.
To continue, slavery was mentioned for the first time by Noah who cursed one of his sons with slavery. Not an invention of God. We were created free. We chose to sin and chose bondage. Slavery to each other was just a natural result of sin.
Divorce was written into the law as Jesus said due to the hardness of men's hearts. It was not so from the beginning. God's perfect will is that a husband love his wife as Christ loves the church.
Capital Punishment, I will have to look up the earliest occurance of that, but I do know that very early in Genesis, we are told that a man who hangs on a tree is cursed. God does not curse people lightly. Indeed, one can read that this is even condemnation of hanging a man on a tree as punishment.
Further, we know that God did not kill Adam and Eve for their sin, not immediately anyway, nor was Cain put to death for his capital crime.
Captial Punishment as found in the law is decreed and ordained to CONTROL the use. It is a warning against vigilantism. In fact, there are provisions in which the charged may escape to various safe spots in the land of Israel to avoid Capital Punishment.
Lisa