There is the matter of initial selection.<p>If this blood turns up at a crimescene, the police know that the person involved was &quot;Born in California since 1983&quot;, a category which shrinks the suspect pool substantially, and can be linked via paternity and maternity to any close relative of someone born in California since 1983.  If there are <i>two</i> or <i>three</i> such relatives and a precise fractional relationship can be determined (I&#x27;m assuming full sequencing), then the venn diagram of these family trees gets incredibly powerful, perhaps even powerful enough that traditional detective work is unnecessary.<p>AFAIK nearest relative I have that was born in California since 1983 is a cousin&#x27;s two children.