Today’s blog is written by guest blogger, Ken Doyle, Promega. Reposted from The ISHI Report with permission.
In the summer of 2012, a ranch worker in Brooks County, Texas, discovered bones scattered in the brush and contacted the county sheriff’s office. Further investigation unearthed a few personal effects and clothing. The remains were buried in nearby Sacred Heart Burial Park, and the case was assigned death record number 0425.
Unidentified human remains (UHR) are not uncommon along the US-Mexico border, and most are assumed to be from undocumented migrants trying to enter the US. In Brooks County, which lacks the financial resources of some border counties in other states, UHR are typically buried without any attempt at identification.
A year after the UHR in case 0425 were discovered, a forensic anthropology team from Baylor University began exhuming the remains of people buried at Sacred Heart, eventually finding over 70 unidentified migrants. Case 0425 was assigned to Dr. Kate Spradley of Operation Identification at the Forensic Anthropology Center, Texas State University. In this case, the skeleton was almost intact, and the remains had tentatively been identified as a Salvadoran woman named Arely Sosa, due to an identification card found near the body. The team used conventional anthropological methods to develop a biological profile. During their inventory, they discovered another identity card inside a shoe. Further investigation of the biological profile, using a missing persons database developed by the Colibrí Center for Human Rights, led to a match with the name on the identity card: María Guardado, reported missing in Honduras. Only now could the team perform DNA analysis. After comparison with family reference DNA profiles obtained by the Argentine Forensic Anthropology Team, María Guardado’s identity was confirmed, two years after her remains were discovered.
“At the age of 37, María left Central America for the United States after her husband had been killed in Honduras,” says Sara Katsanis, MS, who collaborates with the forensic anthropology team. Prof. Katsanis is currently Research Assistant Professor of Pediatrics at Lurie Children’s Hospital, Feinberg School of Medicine, Northwestern University. “María apparently had intended to join her sister in New York, find work, and send money back home to her mother and children in Honduras.”
Prof. Katsanis explains the unique challenges that face the identification of migrants. “Remains of deceased migrants might never be found, might be scattered by animals or scorched by the sun, or otherwise be compromised,” she says. Most migrants travel without identification or with false identification. “Migrants have long been seen as the shadows in American society,” Prof. Katsanis adds, noting that political tensions at the border have increasingly demonized migrants. Unfortunately, these tensions and biases play into policies that determine the best processes for identifying migrant UHR. In some cases, DNA samples are never taken, and bodies are buried without autopsies. Even when DNA samples are obtained, they are not always analyzed for upload into CODIS, the national DNA database maintained by the FBI. The National DNA Index System, which is part of CODIS, is used extensively for missing person identification.
Further complicating the identification of migrant UHR, family members might have difficulty navigating the system to search for their loved one. They may not report the case to law enforcement or even know where to file a report. “They might not trust law enforcement with their genetic samples and might instead go to non-governmental organizations (NGOs) to provide a DNA sample,” Prof. Katsanis says. These problems are not unique to the US-Mexico border. “How DNA data are collected, managed, protected, and shared is a problem that needs consideration across the globe.” A recent publication in Forced Migration Review provides further insight into some of these data-sharing challenges.
Prof. Katsanis relies on her diverse background—forensic and clinical DNA testing, genetic policy, social science, and human rights issues—to address these problems. “Both forensic and clinical environments struggle with management of sensitive genetic information,” she says. “In fact, the issues are similar—cross-contamination risks, misattributed parentage, and revelation of incidental findings.” She stresses the principles of informed consent when it comes to the collection of family reference samples. The privacy safeguards that surround whole-genome data and clinical genomics could be applied to kinship testing.
Advances in forensic DNA technology have made some aspects of solving missing person cases easier. Prof. Katsanis points to improved kinship algorithms and expansion to 20 short tandem repeat (STR) markers as an example. She adds, “Triallelic single-nucleotide polymorphism (SNP) panels have enormous potential for facilitating more distant kinship matching.” Conventional SNP panels usually contain biallelic markers; SNPs with three or more alleles have higher discriminating power, making them especially suitable for analyzing degraded samples. Rapid DNA technology could also help with processing family reference samples. Overall, though, Prof. Katsanis feels these technological advances have not been widely applied in missing person cases.
When it comes to policy, Prof. Katsanis would like to see advances in two areas. The first is an improved strategy for collecting family reference samples, including a common, rolling consent process, and entrusted agents trained for DNA collection outside of law enforcement. Second, she would like a comprehensive strategy to manage UHR and de-identified family reference DNA data outside CODIS. Such a policy would help develop kinship comparisons among all of the data siloed in various databases around the world. Prof. Katsanis admits that these changes, while helpful, will only make a dent in the issues with DNA data sharing and identification of deceased migrants. “Neither will address the systemic bias that results in unnecessary deaths and the resulting, inherent challenges of identifying human remains within an unjust society,” she concludes.
Building a National DNA Program
Across the globe in Australia, over 500 sets of UHR are scattered across morgues, forensic laboratories, and law enforcement archives. Some of these remains constitute just fragments of bones, while others include partial or complete skeletons. These remains have been discovered washed up on beaches, in bush land, at construction sites, or even in the stomach of sharks. Often, the cause of death remains unknown while, in other cases, the evidence points to homicide.
The issue of UHR is part of a larger problem: over 38,000 persons are reported missing in Australia each year. According to the Australian Federal Police (AFP) Missing Persons website, a missing person is officially defined as “anyone who is reported missing to police, whose whereabouts are unknown, and where there are fears for the safety or concern for the welfare of that person.” The AFP further defines a long-term missing person as someone reported missing for more than 3 months and notes that there are over 2,600 people currently listed in that category.
“I first became aware of these statistics in 2011 when I was establishing a mitochondrial DNA testing laboratory in New South Wales,” says Associate Professor Jodie Ward, PhD, Director –Australian Facility for Taphonomic Experimental Research (AFTER), University of Technology Sydney. “From that point on, I started researching how forensic science could help to restore the names and faces of these unknown Australians.”
Most missing person cases are solved within a short timeframe. For the families of those who have never been located, facing the prospect of identifying remains can be an overwhelming emotional experience. And yet, compared to never knowing the answer, a positive identification can bring a sense of resolution.
Dr. Ward has made it her mission to help families struggling when a loved one goes missing. In 2015, she received a Churchill Fellowship to travel abroad and investigate how other countries were successfully using DNA-led approaches to identify large numbers of unidentified and missing persons. Part of her travel included visiting the International Commission on Missing Persons and the University of North Texas Center for Human Identification (UNTCHI). She spent several years devising, publishing, and promoting international best practice recommendations for establishing a national DNA identification program for missing persons in Australia. In 2018, Dr. Ward—a self-described “forensic humanitarian”—presented a TEDx talk in which she made an impassioned plea for the establishment of an Australian national DNA program. She mentioned her unwavering belief that if her own two children were ever missing, the processes she is championing to put in place will ensure she is able to bring them home, dead or alive.
“In 2020, after almost 10 years of advocating for such a program,” Dr. Ward says, “I received the government funding and support needed to establish the National DNA Program for Unidentified and Missing Persons at the AFP.” She currently serves as the Program Lead. Under her direction, the AFP National DNA Program is working together with Australian law enforcement agencies to apply contemporary forensic techniques in current UHR cases, particularly showcasing the power of forensic DNA analysis. The program’s goals include establishing an identity for UHR cases, solving long-term missing person cases, and providing answers to families with missing relatives.
Dr. Ward brings a wealth of experience to the AFP National DNA Program. She has worked on a variety of UHR and missing person cases over the years, including identifying victims from the Black Summer bushfires in 2019–2020. Her work has helped to solve Tasmania’s oldest missing person case dating back to 1955, repatriate 750-year-old ancestral Aboriginal remains, and lay to rest two fallen soldiers from the First World War.
Obtaining usable DNA samples from UHR—often just fragments of bone or teeth—can be challenging. However, advances in forensic DNA techniques have contributed significantly to the identification of UHR. “Autosomal, Y chromosome, and mitochondrial DNA testing of bones and reference samples will be performed using modern genotyping and sequencing equipment,” Dr. Ward says. These methods will help deliver a high-throughput, cost-effective and genetically informative identification workflow. After developing a DNA profile, the next step is trying to find a match—often, by using methods such as forensic genetic genealogy or forensic DNA phenotyping when routine testing approaches are unsuccessful. As Dr. Ward notes, “This suite of DNA intelligence tools now gives renewed hope to those missing person cases that were previously unable to be solved by searching national law enforcement DNA databases.”
She adds that a national DNA database is essential for such efforts to succeed and lists the criteria for an ideal DNA database. It should:
Contain DNA profiles that represent every UHR and long-term missing person case
Use autosomal, Y chromosome, and mitochondrial DNA data in searches
Allow both direct and kinship searching and matching capabilities
Permit searches of UHR and direct reference samples against DNA profiles in all indexes of the database, but restrict searches of DNA profiles from family reference samples against DNA profiles from UHR only
Combining Technology and Genealogy
Both Prof. Katsanis and Dr. Ward cite the pioneering work by UNTCHI in missing person cases. Bruce Budowle, PhD, is the center’s Executive Director. He also has the distinction of attending every ISHI meeting since the very first one in Madison, Wisconsin in 1989.
The University of North Texas Health Science Center, until recently, managed the National Missing and Unidentified Persons System (NamUs) under oversight from the National Institute of Justice. Management is being transferred to the Research Triangle Institute (RTI) International. According to the NamUs website, over 600,000 individuals go missing in the US every year. Approximately 4,400 UHR are recovered each year, with approximately 1,000 remaining unidentified after one year.
Dr. Budowle notes that UNTCHI is in a unique position regarding identification of missing persons, because they do both research and casework. “We’re a CODIS laboratory, so we can upload and do searches in CODIS to help develop investigative leads, solve crime, and identify missing persons,” he says. “And being a university, we also teach and train students and people from the community—professionals who seek help in this area.” He adds that the institute offers its services free to the rest of the country, to help solve missing person cases nationwide.
Forensic genetic genealogy is fundamental to Dr. Budowle’s work in missing person cases. After generating an STR profile, the next step is searching a DNA database—typically, CODIS. “A good percentage of the time…50–70% of the time in the United States, we’re not going to get a hit using a database search,” he says. Next, the team turns to familial searching, to determine if the database may include potential relatives of the missing person. Forensic genetic genealogy can widen the search. “We use dense SNP panels, basically scanning the entire genome and having millions of markers (in theory) that could be used to extend your reach into the potential relative of the source of the material.” Compared to traditional familial searching to identify first-generation relatives, Dr. Budowle explains that genetic genealogy can identify potential seventh- or eighth-generation family members, “if you’re willing to roll up your sleeves and do the post-investigation that’s non-genetic at that point.” Typically, that means a combination of building family trees based on the DNA data and using conventional methods like searching newspaper records, birth certificates, census records, and even old store receipts.
Dr. Budowle is optimistic that the rapid pace of technological development will help solve a greater number of missing person cases. He stresses the importance of having multiple tools at his disposal and having the right tools to meet the specific demands of each case. “If we take that approach, we’re going to solve more cases,” he says, “and that’s our job: to help solve cases.”
Dr. Budowle’s optimism about the potential of technology is echoed by Dr. Ward. “The new era of forensic genomics is proving to be a game changer for unresolved unidentified and missing person cases,” she says. “Massively parallel sequencing (MPS) applications enable multiple genetic markers from multiple compromised samples to be processed simultaneously; decreasing sample processing costs and labor, while increasing the quality and quantity of genetic information obtained.” The AFP National DNA Program will use MPS for mitochondrial genome sequencing as well as for SNP panels developed for ancestry, phenotype, identity, and kinship applications. Forensic genetic genealogy will form a significant part of their workflow.
In addition, Dr. Ward says, “the National DNA Program is also validating non-genetic techniques, such as digital craniofacial reconstructions.” The development of these techniques is reliant on complementary research being conducted at AFTER. Taphonomic facilities “provide forensic scientists with an invaluable opportunity to test and optimize novel technologies on donated human bodies, before applying them to UHR casework.”
Ultimately, technological advances must be accompanied by shifts in policy, especially when facing the challenges of UHR cases involving transnational missing persons. As Prof. Katsanis points out, we’re not there…yet.
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