Here's what God set down on a mountain once: "Thou Shalt Not Kill". Pretty clear, right?
In the context of the commandment 'kill' means murder. We aren't to murder, take a life or lives unjustly. All through the Bible people are justifiably killed; God Himself knocked the stuffins out of pagans, driving them out of the Promised Land to make room for Israel.
Scripture also tells us to be obedient to governments that we live under. If your government has a death penalty for crimes, that government is not murdering criminals, but is being just.
This is also why Christians join the rest of their countrymen in taking up arms in defense of their countries-if your government sends you to war, you are obedient to your government and go.
I wish the Muslims, who pay lip service to Jesus as a prophet while rejecting the idea that God could have a son-I wish that Muslims would take the sign above to heart. It would make for a better world.