The existence of the letter is itself a detail that speaks to something about Lori’s relationship with her daughter. She had plans, even in extremis, that involved communicating across a long time gap to the child she would not see grow up. The content of those plans is not available, and it would not be appropriate to speculate about what a deeply distressed person chose to write to a toddler she was leaving.
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## What Forensic Genealogy Can and Cannot Find
The success of forensic genetic genealogy in the Lori Ruff case has prompted some observers to treat the method as a near-infallible solution to identification problems of this type. That characterization overstates what the method can reliably accomplish.
The method’s success depends on the population of DNA profiles in the consumer databases. As of the mid-2020s, the major databases — Ancestry, 23andMe, and the public database GEDmatch — collectively hold tens of millions of profiles. The United States has a population of approximately 330 million people, and a much larger global population of potential relatives of American subjects. This means that for most subjects, the closest match in the database will be a relatively distant relative — a third, fourth, or fifth cousin — and the genealogical research required to trace a connection from a distant cousin match to a specific contemporary individual can be extensive.
The success of the method also depends on the genealogical research skills of the investigator. The genetic data produces a list of matches with estimated relationship ranges; the genealogist must then do the work of building family trees and identifying which contemporary individual in the right demographic profile matches the genetic signal. This work is time-consuming, skill-intensive, and can be impeded by incomplete genealogical records, restricted vital records in certain jurisdictions, adoptions and other non-paternity events that complicate biological family trees, and the absence of informative records about specific generations.