The verse says "KILL," not "murder".
If God had only meant the verse to mean "murder", He would not have created "cities of refuge" as He did in Numbers 35:9-13, in order to protect the "avenger" and the person who commits involuntary manslaughter and self-defense. .
ALL human life is sacred in God's eyes. Including the life of the unborn. (read Exodus 21:22)