Forensic Genealogy Offers Families the Gift of Closure

By Nancy La Vigne

In 1978, a woman’s body was discovered in Northern Nevada, packed in a garment bag and buried in a shallow grave. Law enforcement actively investigated the crime until all leads were exhausted, and eventually the case went cold. However, the woman was not forgotten, and today she is no longer nameless. In this case, and in many others like it, forensic scientists have finally identified the victim in a decades-old investigation. They’re providing fresh leads for beleaguered detectives. And they’re doing it all with a new kind of DNA evidence called forensic genetic genealogy.

This relatively new technique that most famously aided in the 2018 arrest of the “Golden State Killer” is both promising and somewhat controversial. The method follows distinct differences in an individual’s genes to reveal familial relations that are not detectable through traditional DNA matches, which can yield leads for identifying persons even when the case has scant investigative information. But privacy experts worry about law enforcement’s interaction with consumer data. As a result, a technique that has become useful to law enforcement efforts has also experienced backlash.

Sometimes investigators cannot find a DNA match in the FBI’s DNA database, known as the Combined DNA Index System (CODIS). Forensic genetic genealogy can assist investigators in these circumstances. The advantage simply boils down to a difference in DNA technology: CODIS contains results from more traditional DNA techniques that examine only 20 specific sites in the genome, so-called short tandem repeats (STRs). This technique is very good at matching profiles to individuals—or even close relations such as siblings and parents.

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Forensic genealogy, however, screens hundreds of thousands to millions of distinct variations across a genome, a person’s entire genetic map, capturing connections to their near and distant relations hidden across generations. These single nucleotide polymorphisms (SNPs) illuminate ancestry and links to more distant relatives, increasing the possibility of making an identification.

Unfortunately, genetic genealogy’s usefulness as an investigative tool has been unnecessarily conflated with data privacy, which in the U.S. is given formal protections. Much of the controversy derives from misconceptions about how law enforcement obtains and uses genetic genealogy information in investigations, and how those methods differ from traditional techniques. Contrary to common belief, law enforcement does not receive special access to DNA databases beyond what is publicly available to any database user. They will not arrest a participant based solely on information from the database. Forensic genetic genealogy is just one of many investigative tools used to produce leads and focus investigative efforts. Corroborating evidence is still needed for arrest and conviction.

To be sure, we need transparency, vigilance and governance to ensure that this powerful data source is properly and lawfully used. But genetic evidence itself is irreplaceable (and often irrefutable), and it adds a critical tool to the forensic scientist’s tool kit. When traditional methods have been exhausted, forensic genetic genealogy has been invaluable in establishing familial relationships and identifying unknown individuals. The possibilities of this promising new tool should not be overshadowed by fear and misunderstanding.

In 2018, decades after the Nevada case went cold, state police there submitted details about the unidentified woman to the National Missing and Unidentified Persons System (NamUs) hoping to generate new information about her identity. NamUs is a publicly available national database administered by the National Institute of Justice that currently contains information on 55,845 active missing, unidentified and unclaimed persons’ cases. Investigators also requested analysis of the woman’s remains using NamUs’s forensic services. That enable investigators to match long-term missing persons with unidentified remains. Since 2007 NamUs has resolved 15,109 missing and unidentified persons’ cases using advanced forensic techniques, including forensic genetic genealogy. Of those, 1,412 were declared homicide victims.

In 2022 NamUs finally solved the mystery of the woman’s identity, providing closure to relatives who had been wondering about her since she had left home with her boyfriend for the Pacific Northwest in the early 1970s. Forensic genetic genealogy led investigators to the other side of the country and two possible relatives. They discovered that the woman was Florence Charleston, still remembered by her two nieces whose DNA helped identify her.

Charleston’s tragic murder and the decades-long quest to identify her remind us how far forensic science advanced in those intervening years. Entering Charleston’s information into NamUs was the catalyst for discovering her identity, which was confirmed through DNA from her nieces using advanced genetic forensic technologies.

The people behind these cold cases matter, and so does understanding the circumstances around their deaths. Prosecutors, judges and juries give considerable weight to forensic evidence, so it is essential to support studies that measure the accuracy of forensic techniques and the influence of forensic evidence on convictions. Research bolsters our justice system’s fairness and informs forensic experts on the most reliable methods—as well as their limitations. When forensic professionals make statements in court, they must be supported by sound science.

An effective legal system provides closure and delivers justice for victims and their loved ones. Forensic scientists continue to find new ways to glean critical information from crime scenes and support prosecutions for unsolved cases. We have witnessed life-changing innovations in the last 46 years, especially in DNA technology. Now, more than ever, forensic science offers hope to many who may have thought that, for them, justice might never be served.