Pickens writes "The oldest genetically identifiable nuclear family met a violent death, according to analysis of remains from 4,600-year-old burials in Germany where the broken bones of these stone age people show they were killed in a struggle. Comparisons of DNA from one grave confirm it contained a mother, father, and their two children. 'We're really sure, based on hard biological facts not just supposing or assuming,' says Dr. Wolfgang Haak, from The Australian Centre for Ancient DNA. The stone-age people are thought to belong to a group known as the Corded Ware Culture, signified by their pots decorated with impressions from twisted cords. The children and adult males had the same type of strontium in their teeth — which was also found locally, but the nearest match to the women's teeth was at least 50km away, suggesting they had moved to the area. 'They were definitely murdered, there are big holes in their heads, fingers and wrists are broken,' says Dr. Alistair Pike from Bristol University. He noted that one victim even had the tip of a stone weapon embedded in a vertebra. 'You feel some kind of sympathy for them, it's a human thing, somebody must have really cared for them. ... We don't know how hard daily life was back there and if there was any space for love,' added Dr. Haak."