Forensic techniques that are used to solve modern homicide cases helped American anthropologists reveal family resemblances in 2,000-year-old skulls from the Roman Empire. The study used a statistical technique known as geometric morphometrics to identify similarities in skulls from three Italian graveyards dating from between the first and third centuries A.D., when the Roman Empire was at its height. Precise three-dimensional measurements of dozens of skulls from two of the graveyards showed distinct regional differences, which the researchers interpreted as a sign of a common ancestry among many people in those regions.