But does it have to?
In the early Middle Ages, Anglo-Saxon and Germanic societies found a way to establish, as a community, a way to settle the matter of a death in a legal and tidy system: wergild (Old English wer = "man"* + gild = "tribute/gold").
The practice was first established by Æthelbert of Kent (c.560-616). The Anglo-Saxon Chronicle tells us that Æthelbert held sway over the other Anglo-Saxon kingdoms in Britain. He was the first English ruler to convert to Christianity, and perhaps wergild was his attempt to cool the hot blood of the Anglo-Saxon culture. Within a couple centuries, wergild was being used for theft, rape, breach of peace and many other crimes and misdemeanors. Wergild allowed a community to move on after monetary retribution.
How much retribution? It was different for different areas and times. In Kent in the 8th century, a cow was worth a shilling; a freeman was worth 100 shillings, and a nobleman 300. Elsewhere, a sheep might be worth a shilling, and a nobleman worth 1200 sheep. Only slaves were worth too little to account for.
Afghanistan. Wergild also appears in The Lord of the Rings, when Isildur refuses to throw the One Ring into Mount Doom when he had the chance, instead claiming it "as wergild for my father and brother." In his case, however, wergild created a larger problem than it solved.