Blood, Blood-Guilt, & the Death Penalty

What does it mean that, "The voice of your brother's blood is crying to me from the ground." in Genesis 4:10? Why does God say, "Whoever sheds the blood of man, by man shall his blood be shed, for God made man in his own image." in Genesis 9:6? What is the role of the civil magistrate in the shedding of blood? In this video we explore answers to these questions.