To determine year of death, the researchers used radiocarbon levels in soft tissues. Unlike tooth enamel, soft tissues are constantly being made and remade during life. Thus, their radiocarbon levels mirror those in the changing environment.

What can carbon dating be used to determine the age of?

Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon.