Is capital punishment right when God says "thou shalt not kill"?

Does God's Word support capital punishment?

Yes. God's decree to Noah in Genesis 9:6 has never been rescinded, "Whoso sheddeth man's blood, by man shall his blood be shed: for in the image of God made he man." In Romans 13:4 we read about civil leaders, '...for he beareth not the sword in vain: for he is the minister of God, a revenger to execute wrath upon him that doeth evil." The reference to "the sword" would indicate that civil rulers have the God-given right - and responsibility – to execute capital punishment when it is necessary to do so justly. However, the Word of God does protect the innocent by teaching that there should be clear proof of guilt before anyone is put to death. We read in Deuteronomy 17:6, "At the mouth of two witnesses, or three witnesses, shall he that is worthy of death be put to death; but at the mouth of one witness he shall not be put to death."

W. Gustafson