The Gatekeepers' Dilemma
Biological anthropologists are often the last responders to, and gatekeepers for, unidentified skeletonized human remains from criminal investigations. Bones from forensic cases wind up in our labs when they are deemed largely unidentifiable due to poorly preserved, disturbed, or damaged key elements (e.g., skull or pelvis) forestalling identification. Remains with uncertain provenance or origin also coalesce in the anthropologist’s lab, creating a motley mix of inherited remains through years of personnel turnover and retirements. Working with unidentified remains can feel like an arduous and impossible duty; semester after semester, we pull out the familiar box of bones from the cabinet, hoping that a talented student may see something previously overlooked or that new published methods might offer novel recourse. Anthropologists are long game scientists, working toward the refinement of methods and making interdisciplinary connections that aid our end goal: positive identification of decedents.
Figure 1. Students at the University of New Hampshire analyze human remains from an archaeological site in Dr. Amy Michael’s Human Osteology course. (Courtesy of Amy Michael)
Biological anthropology is a holistic discipline, focused on the intersections of biology, culture, and environment, to frame how life and death experiences affect the skeleton. Building a biological profile of age, sex, body size, and ancestry of a decedent from skeletal remains is the principal contribution of anthropological methods to medico-legal cases (Figure 1). Coupled with archaeological excavation, trauma analysis, post-mortem interval (PMI) estimation, and isotopic and other chemical analyses, anthropologists can aid in producing a comprehensive decedent profile and perimortem timeline. However, for many unidentified remains, particularly those in which bones are fragmentary or damaged, genetic analysis may be the only avenue for identifying unidentified human remains.
Advanced Genetic Analysis has Transformed how Human Remains are Identified
While CODIS testing will remain the workhorse of forensic DNA testing for years to come, countless solvable cases remain unsolved due to the limitations of this robust, but antiquated test method. CODIS testing is especially ineffective for unidentified individuals as many of them are victims and the FBI database is primarily composed of DNA profiles for convicted criminals. Furthermore, unidentified remains sometimes predate the widespread use of CODIS testing.
Fortunately, advances in DNA testing and genetic genealogy have been steadily helping forensic professionals close a growing number of seemingly “unsolvable” cases. The newer DNA testing methods rely on “reading” hundreds of thousands of DNA markers across the genome. There was early (albeit limited) success in collecting genome-wide markers using SNP microarrays. However, while SNP microarrays (sometimes called SNP chips) power recreational DNA testing methods for ancestry and genealogy, they are not effective for degraded, contaminated, or mixed DNAs – the bread and butter of forensic DNA. Moreover, arrays provide little indication that they are failing as they fail, so even if a result is returned, it is difficult to assess confidence in the DNA markers that are measured. Inaccurate data can have catastrophic effects on downstream genealogy efforts and prevent otherwise straightforward paths to human identification.
The better approach, especially for degraded and contaminated human remains, is to leverage massively parallel sequencing (MPS) techniques. Although more complex to utilize than SNP microarrays, MPS is more robust and accurate. For example, Othram’s Forensic-Grade Genome Sequencing method is based on MPS. The method combines MPS and advanced informatics to digitize genomes that otherwise fail with SNP microarrays and other non-sequencing methods. Genomic information is pieced together, leveraging multiple layers of quality data for every DNA position that is measured, to ensure accuracy. Importantly, sequencing detects novel genetic variations with exactly the same efficiency as previously seen variants and this can be used to minimize the types of error and bias intrinsic to microarrays and other methods, especially when working with imperfect forensic evidence. Finally, it is possible to combine sequence data (this cannot be done for SNP microarrays), so if insufficient data is generated from one test, results from multiple sequencing tests can be combined to produce an accurate representation of the DNA markers. The ability to iteratively and accurately collect DNA data from forensic evidence is critical to the success of genetic genealogy. Imperfections and incomplete information can obscure distant genetic relationships that are key to establishing identity.
The efforts of anthropologists, genomic scientists, and genealogists can be seen as nested approaches in the vein of anthropological holism (Figure 2). Experts from these disparate fields unite critical pieces of information in a triad strategy that has enabled identification of cold case victims.
Figure 2. The triad approach to restoring the identity of human remains.
To showcase the power of this triad approach, we provide two examples in which teams of anthropologists, forensic DNA scientists, and genealogists united to solve the identity of human remains that could not be reached using traditional anthropological or CODIS testing methods.
The Buffalo Cave Torso
In late summer of 1979, a young girl and her family hunting for artifacts in the cool, dry depths of a lava tube cave outside the small town of Dubois, Idaho found instead a mummified and headless human torso wrapped in burlap and dressed in tattered clothing (Figure 3).
Figure 3. One of Joseph Henry Loveless’ socks preserved for 103 years (left) and a view from inside the Buffalo Cave lava tube cave where the remains were discovered (right). (Courtesy of Samantha Blatt)
Though the Clark County Sheriff suspected these to be the remains of an old-time gambler, the lingering pungent odor led the coroner to believe that the body could not have been in the cave for more than 5 years. Analyses by the FBI, as well as Smithsonian anthropologist Dr. Douglas Ubelaker, concluded that the remains were those of a probable male of European ancestry aged approximately 40 years old at the time of death and dismembered above the elbows and knees. In 1991, the limbs were discovered in a similar manner, again in a burlap sack. At that time Idaho State University conducted a search and systematic excavations and again in 2015. The skull was never recovered and the PMI estimation remained wide and uncertain, so the approximate date of burial was considered early to mid-1970s. The case went cold.
In 2019, Dr. Amy Michael (University of New Hampshire) and Dr. Samantha Blatt (Idaho State University) became acquainted with Anthony Redgrave and Lee Bingham Redgrave, at the time genealogy team leaders at the DNA Doe Project (DPP) and now lead genealogists at Othram. The team saw the potential for identifying the remains using genetic genealogy. Previous STR testing did not reveal an identity, so permission was secured from the Clark County Sheriff’s Office to submit the case to DDP. A full genome sequence of the degraded remains was then digitized at the Othram forensic sequencing laboratory (Figure 4). Armed with the biological and genetic profile, as well as case history, DDP assembled a team of 14 volunteer genealogists that spent approximately 2,000 hours working to establish an identity by searching family trees of genetic relatives.
Even after the genetic markers of the individual were interpreted, the missing skull and uncertain PMI in this case were substantial challenges for the team. The skeletal remains bore clues that the decedent was middle-aged and suffered from slight arthritic bone degeneration and the clothing was not contemporary. Descriptions of clothing, original incident reports, and the biological profile served as critical clues guiding genealogists as they delved into witness accounts from regional newspaper articles and arrest records. Weaving all resources together, a family tree of over 31,000 relatives was constructed and narrowed down by DDP volunteers over 15 weeks. Finally, a presumptive identification was made. Deputy John Clements of the Clark County traveled to collect a comparison sample willingly submitted by the closest living kin: an 87-year old grandchild.
Figure 4: A senior forensic scientist at Othram prepares DNA samples for forensic sequencing. The Othram laboratory features necessary elements of forensic DNA work, such as pre- & post-amplification separation, and unidirectional workflow. (Courtesy of Othram Inc.)
The work of anthropologists, forensic DNA scientists, and genealogists led to one of the oldest forensic cases ever resolved using autosomal DNA testing and genetic genealogy. The victim, Joseph Henry Loveless (b. 1870, d. 1916), had been deceased for 103 years before he was identified. The PMI was 60+ years off, much to the shock of all involved and the local community when the identity of the man in the cave was announced on New Year’s Eve 2019. Loveless was a Wild West outlaw, bootlegger, and murderer with many aliases and jailbreaks during his life.
Mississippi County “Harry”
Another recent case highlights the utility of these intersectional efforts. In 1979, unidentified burned human remains were discovered in an agricultural field near Charleston, Missouri and turned over to the Anthropology department at Southeast Missouri State University (SEMO) after the investigation stalled. In 2013, Dr. Jennifer Bengtson and her students began to re-analyze the case (Figure 5). Traditional STR profiling by University of North Texas Center for Human Identification did not yield an identity for the individual. As with the Idaho case, Dr. Bengtson had hit an investigative wall. There was little more to learn about the remains until the SEMO team turned to forensic genomics and genealogy.
Dr. Bengtson sent a small sample of the remains to Othram in early 2020 in the hopes that a full genome profile would enable an identification. The SEMO John Doe remains were not nearly as well preserved as the Clark County John Doe remains and the thermal damage to the remains was a considerable challenge, both in developing an anthropological profile and performing DNA testing. Heat degrades DNA making testing more difficult. Further complicating the case was the bacterial content that had contaminated the already damaged remains. Othram combined DNA extraction techniques with methods for enriching human DNA and produced a digitized genome sequence from the degraded and contaminated bone.
Figure 5. SEMO students in Dr. Jennifer Bengtson’s class forensic anthropology methods. (Courtesy of Southeast Missouri University)
The genetic analysis and genealogical research revealed that the individual was related to the Creole-speaking Missouri French who initially settled Illinois County in the early 18th century. Anthony Redgrave and Lee Bingham Redgrave led the team of genealogists who developed a tree and eventually submitted a name for confirmation. The victim was identified as male in his 30s who had drowned in the Mississippi River many decades prior. While the family requested privacy and his full name has not been released, they generously allowed some of his story to be shared, including that he went by the name “Harry.” After significant flooding in the area, the body washed up on a farm and was accidentally burned during field maintenance. A careful anthropological assessment by Dr. Bengtson revealed taphonomic changes consistent with the decomposition and burning process, and her age at death estimation was used by genealogists as they worked through the family trees to make an identification. After 41 years, “Harry” was finally identified and returned to his family.
Checklist for Successful Identification of Human Remains
The cases presented here demonstrate the possibility of establishing forensic identifications from skeletonized human remains that failed to be resolved through traditional methods. As of May 2020, there are more than 13,300 recorded unidentified sets of remains in NamUs.gov, which is a substantial underestimate of the total unidentified remains in the United States. We envision a future in which teams of anthropologists, forensic DNA scientists, and genealogists collaborate to establish identities for these unknown persons.
We offer the following checklist as the outcome of our shared learning experiences from the cases detailed above and hope that these considerations will prepare teams for strategic comprehensive analysis of unidentified human remains.
ANTHROPOLOGISTS
FORENSIC DNA SCIENTISTS
GENEALOGISTS
✔ Involvement in consultation, excavation, and/or exhumation when necessary.
✔ Determine the best approach for DNA testing considering quantity and quality of the DNA evidence.
✔ Shared access to context clues, including pictures of clothing and accessories.
✔ Construction of biological profile.
✔ Account for mixtures and for non-human contaminants.
✔ Use genetic matches from multiple genealogical databases to build out trees for genetic relatives.
✔ Consideration of trauma, pathology, and individualizing discrete traits.
✔ Access all parts of the genome including mtDNA and yDNA to build the most complete genetic profile.
✔ Integrate public records, newspapers, and historical data sources to contextualize genealogical matches.
✔ Re-analysis of legacy collections using modern methods.
✔ Reconstruct as much of the unknown person’s genome as possible to enable genealogical database searches.
✔ Work collaboratively with investigators to include and exclude potential matches merging evidence, context, and the biological profile with genetic matches and public records.
✔ Maceration of remains, skeletal photography, sampling in consultation with DNA scientists.
✔ Facilitate confirmation testing to genetically confirm identifications made through genealogy.
✔ Document how genealogical matches were included and excluded during the investigation.
ANTHROPOLOGISTS
✔ Involvement in consultation, excavation, and/or exhumation when necessary.
✔ Construction of biological profile.
✔ Consideration of trauma, pathology, and individualizing discrete traits.
✔ Re-analysis of legacy collections using modern methods.
✔ Maceration of remains, skeletal photography, sampling in consultation with DNA scientists.
FORENSIC DNA SCIENTISTS
✔ Determine the best approach for DNA testing considering quantity and quality of the DNA evidence
✔ Account for mixtures and for non-human contaminants.
✔ Access all parts of the genome including mtDNA and yDNA to build the most complete genetic profile.
✔ Reconstruct as much of the unknown person’s genome as possible to enable genealogical database searches.
✔ Facilitate confirmation testing to genetically confirm identifications made through genealogy.
GENEALOGISTS
✔ Shared access to context clues, including pictures of clothing and accessories.
✔ Use genetic matches from multiple genealogical databases to build out trees for genetic relatives.
✔ Integrate public records, newspapers, and historical data sources to contextualize genealogical matches.
✔ Work collaboratively with investigators to include and exclude potential matches merging evidence, context, and the biological profile with genetic matches and public records
✔ Document how genealogical matches were included and excluded during the investigation.
Moving Forward with Collaborative Approaches
A combined triad strategy, as described here, can be systematically applied to clear legacy collection cases like those in anthropology labs, as well as NamUs cases. The nested analysis, beginning with anthropological study of remains, provides necessary clues for genealogists as they develop ancestry trees. Further, many anthropologists have the skills and/or connections for isotope sampling which can narrow decedents’ geographic region during childhood or recently before death and greatly assist in compiling match lists. Other anthropological methods, such as examination of bone microstructure, analysis of dental calculus, and radiographic imaging, can aid in establishing forensic significance, circumstances of burial, diagenetic and taphonomic alteration, dietary context, and other clues that may generate a suite of identifying traits. Together, anthropologists, forensic DNA scientists, and genealogists can tell holistic and individualizing stories from remains. The science behind each discipline guides us toward the ultimate goal: personal identification and the recovery of a lived or chosen name.
Dr. Samantha Blatt, Ph.D.
Idaho State University
Dr. Samantha Blatt is currently an Assistant Professor at Idaho State University. She received her Ph.D. from The Ohio State University in biological anthropology with an emphasis on bioarchaeology and dental anthropology. Her research interests have focused on the histological microstructures of dental and skeletal tissues, disease, growth, and childhood in ancient North America, forensic and archaeological taphonomy and diagenesis of teeth, microscopic imaging, and individualizing skeletal traits. She is particularly interested in using innovative methods to revitalize cold cases, has worked with numerous NAGPRA-related skeletal remains, and is devoted to community archaeology. Her work with museum collections and preservation offices includes analyses of 40,000 year old canids, shrunken heads, prehistoric and historic dental calculus, cannibalized remains from the Cook Islands, and an Incan mummy. She works closely with co-author Dr. Amy Michael on numerous forensic and archaeological projects related to these interests.
Dr. Amy Michael analyzes a thin section of human femur bone. (Courtesy of Amy Michael)
Amy Michael, Ph.D.
University of New Hampshire
Dr. Amy Michael is a biological anthropologist at the University of New Hampshire specializing in the investigation of human bone and tooth microstructure in an effort to answer anthropological questions about past and modern people. She received her Ph.D. from Michigan State University in biological anthropology with a focus on the bioarchaeology of the ancient Maya of Central Belize. Trained in bioarchaeology, forensic anthropology, and historical archaeology, Dr. Michael is interested in applying skeletal biology methods to how cultural and environmental processes affect the human skeleton. Dr. Michael has worked on mortuary and historical archaeology projects in Belize, Albania and the United States. Recent projects have included novel approaches to identifying transgender and gender variant cold case victims, investigations of household corrosives on the forensic identification of human teeth, assessments of foot pathologies in ancient Maya burials, and explorations of the effects of carnivore digestive processing on human bone microstructure in recovery scene contexts.
David Mittelman, Ph.D.
Othram Inc.
David Mittelman is the founder and CEO of Othram Inc, the world's first private DNA laboratory built specifically to apply the power of modern parallel sequencing to forensic evidence. The laboratory specializes in recovery, enrichment, and analysis of human DNA from trace amounts of degraded or contaminated materials. Mittelman has studied and developed DNA testing methods his entire career. He participated in the Human Genome Project while at the University of Texas Southwestern Medical Center and later received his PhD in Molecular Biophysics from Baylor College of Medicine. He completed his postdoctoral training at Baylor’s Human Genome Sequencing Center, and started his own NIH-funded research program as an associate professor at Virginia Tech. He later spent several years developing technology for DNA testing for medical and consumer genomics applications. Follow Othram on Twitter @OthramTech or visit https://request.othram.com to learn more about how DNA testing could help with your case.