The reason murder is so serious, the reason it gets the death penalty, is rooted in the fact that God made mankind in his own image.

Human value comes from the image of God in us. So to destroy a human life

it has nothing to do with their place in society, their status in this world, their wealth or influence, free man, slave owner or slave... If you kill someone you have destroyed an image bearer of the Creator God. There is an equality here that is significant.