The Era of Investigative Genealogy
Misty Gillis, Investigative Genealogist
August 2025
Investigative Genetic Genealogy (IGG), also known as Forensic Genetic Genealogy, was introduced in early 2018 and remains an emerging technology in the field of investigation. Considering the prevalence in headlines around the world, we’re going to take a look at the history of the revolutionizing tech and some key milestones in the field.
IGG’s roots trace back to over almost two decades ago, when genealogists began to see success using Direct-to-Consumer SNP testing to resolve family mysteries, such as adoption or misattributed parentage. There was a thought that if genetic genealogy can identify unknown biological family members, why can’t the same be done for unknown crime scene sample contributors and unidentified human remains. This was also around the time Parabon NanoLabs began using single nucleotide polymorphism (SNP) testing, commonly used in the medical field, for law enforcement purposes. This marked a turning point for law enforcement. Traditionally limited to just 20 STR markers used in the CODIS database, the field could now leverage thousands of genetic markers to generate new leads in cold and active cases.
With access to these hundreds of thousands of genetic markers, IGG allows genealogists to link unknown DNA samples to much more distant relatives, with confidence out to third cousins, and potentially out to as far as fifth cousins and beyond, as opposed to just a 1:1 comparison that CODIS provides. Using these matches, genealogical trees are built and refined, where a skilled genealogist can trace patterns and intersections among relatives to zero in on where an unknown subject might fit within a family tree.
In this early era, another development was in full swing since 2011. Y-STR testing utilizes the Y-profile (only available for males, who receive their Y chromosome from their father) from an unknown and compares it against the Y-DNA public databases. The idea is that this would generate Y-DNA matches that would provide the contributor’s likely surname. This technology was instrumental in the arrest of Bryan Patrick Miller in 2015 for the Phoenix Canal Murders. The Phoenix Canal Murders are what the vicious murders of Angela Brosso and Melanie Bernas were called that occurred in the 1990s in Arizona. Utilizing this technology, Dr. Colleen Fitzpatrick was able to supply the police department with the surname “Miller”, which assisted with their investigation into the offender.
In late 2017, Parabon NanoLabs and CeCe Moore began working on two unidentified human remains (UHR) cases using data from GEDmatch, while the DNA Doe Project, a non-profit founded by Dr. Margaret Press and Dr. Colleen Fitzpatrick, launched groundbreaking efforts to restore names to UHRs nationwide.
In early April of 2018 the first major milestone had been achieved: the identification of Marcia King, also known as “Buckskin Girl”. This marked the first public use of IGG to identify a set of unidentified human remains.
“Buckskin Girl” was the moniker given to an unidentified female found murdered in Troy, Ohio in 1981. She was located wearing a buckskin style poncho and remained unidentified for 37 years. In 2018, the DNA Doe Project, that now boasts over 140 positive identifications, identified her as Marcia Lenore Sossoman King, a 21-year-old last seen by her family in 1980.
Then, just weeks later, a watershed moment occurred that sent shockwaves through both the forensic and genetic genealogy communities: the Golden State Killer was identified through IGG.
The Golden State Killer (GSK) was the nickname given to an unidentified perpetrator who terrorized California in the 1970s and 1980s. Responsible for at least 13 murders, along with numerous sexual assaults and burglaries, his identity remained a mystery for decades—until 2018, when Joseph DeAngelo was arrested by the Sacramento County Sheriff’s Office. He became the first criminal ever publicly identified using IGG, with the assistance of investigative genetic genealogist Barbara Rae-Venter.
The above two cases revolutionized the application of genetic genealogy, a field once focused primarily on identifying long dead ancestors and adoption/misattributed parentage cases. Now, it was solving violent crimes and long-standing identity mysteries.
Since then, the field has rapidly advanced and we’re going to take a look at some of the key breakthroughs and milestones of the industry.
One of the key breakthroughs was the ability to obtain SNP profiles from rootless hair. While DNA extraction from rooted hair had been a standard practice since the 1990s, developing a DNA profile from hair without a root was previously thought to be impossible. That changed in 2018, thanks to Dr. Ed Green, a professor of biomolecular engineering at the University of California, Santa Cruz. His lab demonstrated that even without the DNA-rich bulb of the hair, a viable SNP profile could still be generated.
This innovation was publicly validated in August 2021, when the Newport Beach Police Department announced that Kenneth Marks had been identified as the person responsible for the 1980 homicide of 42-year-old Judith “Judy” Nesbitt. Judy, a mother of four, was showing the families 36-foot cabin cruiser “The Felicidad IV” to a potential buyer. This showing ultimately led to her death, with her being found shot in the head and her belongings ransacked. In 2018, a rootless hair sample from the crime scene was successfully processed by Green Laboratories, LLC and the resulting SNP profile handed over to Parabon and their Chief Genetic Genealogist, CeCe Moore. Using IGG techniques, Moore built a family tree from the SNP profile and helped identify the source of the hair. Further investigation by law enforcement led to Marks being named as the perpetrator.
Next came another impactful moment in the field of Investigative Genetic Genealogy: its first use in an exoneration. To understand how this innovation unfolded, we need to go back to the 1996 homicide of 18-year-old Angie Dodge in Idaho Falls, Idaho. On June 13, 1996, Angie was found murdered in her apartment, she had been sexually assaulted and stabbed more than 14 times.
Despite the presence of DNA from an unknown male at the scene, police focused on Christopher Tapp, a friend of Angie. After a lengthy and coercive interrogation, Tapp confessed to the crime. In 1998, he was convicted and sentenced to 30 years to life in prison, even though his DNA did not match any of the evidence recovered from the scene.
Angie’s mother, Carol Dodge, refused to give up on finding the truth. In 2019, investigators sent the unidentified DNA sample to Parabon NanoLabs, where genetic genealogist CeCe Moore used IGG to identify a new suspect: Brian Leigh Dripps Sr., a former neighbor of Angie. Investigators covertly collected a cigarette butt from Dripps, and the DNA was a direct match to the crime scene. Within 24 hours of being confronted, Dripps confessed to the sexual assault and murder of Angie Dodge, leading to the formal exoneration of Christopher Tapp, more than two decades after his wrongful conviction.
But 2019 wasn’t over yet and it also marked a pivotal year in forensic history, as it also saw the first trial conviction where Investigative Genetic Genealogy (IGG) was the primary tool used to identify the suspect.
The story begins back in 1987, when Jay Cook (20) and Tanya Van Cuylenborg (18) embarked on a road trip from Saanich, British Columbia, to Seattle, Washington, a journey they would tragically never complete. Their bodies were later found at separate locations in Washington State, victims of homicide. Despite DNA evidence collected at the time, the case went cold due to no matches in the CODIS database.
Immediately following the ground-breaking GSK announcement, in late April 2018, Snohomish County Detective Jim Scharf requested genetic genealogy analysis by Parabon. Genetic genealogist CeCe Moore played a crucial role in the investigation, generating a high confidence lead that led to the arrest of William Earl Talbott III in May 2018.
The following year, in 2019, Talbott was convicted of two counts of aggravated first-degree murder and sentenced to life without the possibility of parole, marking a landmark case for the use of IGG in criminal justice.
These milestones were foundational and have led us to where we are today in 2025.
Daily announcements are being made by a range of practitioners providing critical IGG leads to police departments across the country and around the world. We’re now seeing casework being performed in Canada, as well as Australia and Sweden. We are also seeing the application of IGG in active cases – no longer is this technology only being used for what was deemed a “cold case” but is being utilized to stop would-be repeat offenders in their tracks. These advancements have also brought about state legislation being written to govern its usage, as well as professionalization of the field with the establishment of IGGAB – the Investigative Genetic Genealogy Accreditation Board and other efforts to establish best practices.
As Investigative Genetic Genealogy continues to evolve, it is reshaping the way justice is pursued, giving names to the nameless, resolving decades-old cold cases, correcting miscarriages of justice, and even preventing future crimes. What began as a hopeful extension of family research has now become one of the most powerful tools in modern forensic science. With international adoption, increasing legislative oversight, and a growing community of ethical practitioners, IGG stands at the intersection of science, justice, and humanity. And while its future will undoubtedly raise new questions and challenges, one thing is certain: the era of Investigative Genetic Genealogy has only just begun.
Misty Gillis
Investigative Genealogist, Parabon Nanolabs
Misty Gillis has been a traditional genealogist for over 10 years focusing on US , Canadian and UK genealogy. Gillis began her career in genetic genealogy after she helped her grandfather discover the identity of his own father. She then decided to direct her passion and self-made expertise in genealogy research into a full-time career helping to identify human remains and cracking cold-case homicides and sexual assaults. She has helped solve more than 100 cases and works closely with law enforcement exclusively on criminal cold case files. In her free time, Misty volunteers her expertise to find relationships for adoptees and people seeking answers about their family tree. She is currently employed as an Investigative Genetic Genealogist at Parabon Nanolabs.