Is capital punishment scriptural?

Yes. From the earliest scriptures, to those found in the last book, Godgives his commandment for capital punishment, when justified.He says in Genesis:

"Whoso sheddeth man's blood, by man shall his blood be shed: for in theimage of God made he man." (Genesis 9: 6)

Since God is the same yesterday, today and, forever, His opinion of capitalpunishment for those who take the life of another through the act of murder,has not changed. The thing called "murder" doesn't equate to taking life inthe case of defending oneself, or in the act of military war engagementsthat defend the God-given rights of man. Killing in such instances are evencommended throughout the Bible.

The last book in the New Testament maintains God's same attitude aboutmurder. In the following two instances, God sees the followers of Antichristas murdering God's righteous saints. He prescribes capital punishment forthese vile acts.

"And if any man will hurt them, fire proceedeth out of their mouth, anddevoureth their enemies: and if any man will hurt them, he must in thismanner be killed." (Revelation 11: 5)

Rev "He that leadeth into captivity shall go into captivity: he that killethwith the sword must be killed with the sword. Here is the patience and thefaith of the saints." (Revelation: 10)