Genesis 9:6
"Whoever sheds man's blood, by man his blood shall be shed...
Numbers 35:31-33
'Moreover you shall take no ransom for the life of a murderer who is guilty of death, but he shall surely be put to death... So you shall not pollute the land where you are; for blood defiles the land, and no atonement can be made for the land, for the blood that is shed on it, except by the blood of him who shed it.'
Ezekiel 13:19
"And will you profane Me among My people... killing people who should not die, and keeping people alive who should not live...?"
Jesus continued to teach the requirement of the death penalty, quoting the commandments that He personally gave to Moses:
Matthew 15:3-4
"Why do you also transgress the commandment of God because of your tradition? For God commanded, saying... `He who curses father or mother, let him be put to death.' But you say..."
Mark 7:8-11
"For laying aside the commandment of God, you hold the tradition of men..." [Jesus] said to them, "All too well you reject the commandment of God, that you may keep your tradition. For Moses said, 'Honor your father and your mother; and 'He who curses father or mother, let him be put to death.' But you say..."
The result of not administering a swift and effective death penalty? A murder epidemic, like we have in America today.
Ecclesiastes 8:11
Because the sentence against an evil work is not executed speedily, therefore the heart of the sons of men is fully set in them to do evil.