The Commandment "Thou shalt not kill?" The original Hebrew word for this is "Ratsach" and the correct translation is to murder, slay, kill to murder,(intentional) (premeditated) This is the difference between the words Murder and Kill... Murder is the unlawful taking of a human life for no reason. The command not to murder applies to human beings only. Although God gave animals to mankind for his own use (Genesis 1:26-30; 9:1-4) he shouldn't mistreat them or take for granted the environment (Genesis 2:15; Deuteronomy 22:6-7; 25:4; Proverbs 12:10).
According to the Bible all killing is not murder. Under the Old Covenant God allowed the Israelites to kill other humans under very special circumstances such as punishment for certain sins, for example, murder and in defense of yourself or your family, or justified warfare. God understands that there is a need for killing. One verse regarding self-defense is Exodus 22:2-3 tells us "If the thief is found breaking in, and he is struck so that he dies, there shall be no guilt for his bloodshed. If the sun has risen on him, there shall be guilt for his bloodshed. He should make full restitution; if he has nothing, then he shall be sold for his theft." In this verse it states, "If the sun has risen on him", this means if he has been caught and is no longer a threat you cannot kill him, so God does have provisions for doing the right thing.