‘A cold case is not a closed case’
For more than 30 years, family members of Robert Mullins held out hope that one day he would show up at their door. Maybe the 21-year-old had left Columbus to start a new life somewhere else — in Florida or Mexico, perhaps. His relatives could see him doing that.
Whatever the case, his sudden disappearance and prolonged absence cast an increasingly dark cloud over the family as months and then years piled up. His mother, Catherine, hired an investigator and, as a last resort, consulted psychics. When she died eight years ago, her heart remained broken, the mystery she’d struggled with since the late 1980s still unresolved.
Thanks to dramatic advances in DNA analysis, the dedication of two generations of investigators, and the partnership of BCI’s DNA lab, the Mullins family finally received closure in December: Skeletal remains that hunters found in November 1991 in a shallow grave in a Pickaway County farm field were identified as those of Robert Mullins.
“It’s shocking and sad, and nobody wants to get news like this,” said David Mullins of Columbus. “But it’s a blessing to know they didn’t give up on my little brother and are still working to find out who did this to him.”
Investigators traveled a long, difficult road to restore Robert Mullins’ identity, but they had to wait for the road to be completed before they could get to where they needed to go.
At the time that the bones were found, forensic DNA analysis was in its infancy; the first use of this science in a U.S. criminal court had taken place only four years earlier, in 1987. In fact, the forensic tool that would finally solve the mystery — called genetic genealogy — wouldn’t be introduced until 2018, a full 27 years after the bones were discovered.
Lt. Dale Parish of the Pickaway County Sheriff’s Office and County Coroner Dr. Michael Geron — both now retired — were central to the investigation from the start. A thorough examination of the site yielded only the skeleton, minus the skull; no clothes or other items that might have helped identify the remains were found.
Parish and Geron quickly enlisted the help of a Purdue University researcher who, based on his knowledge of insects found at the burial site, estimated that the body had been in the ground for no more than three years.
With the start of a timeline in place, the next step was to determine the physical attributes of the victim and then cross-reference the information with missing-person reports. Unfortunately, because the state of forensic anthropology was nowhere near as advanced as it is today, investigators were misdirected: Two professors had concluded the remains were female, about 25 years old. What threw them was the victim’s small size, somewhere between 5 feet 1 and 5 feet 4.
For Lt. Parish, the two decades from 1991 to 2011 amounted to a quest for any lead that might advance the investigation. Early on, the bones were sent to the Ohio Bureau of Criminal Investigation (BCI) and the FBI lab, but extracting a usable sample of DNA proved difficult.
A major break came in 2012, when BCI sent the bones to the Center for Human Identification at the University of North Texas, one of the leading DNA testing sites in the nation. The results were jaw-dropping: The victim was actually a male, one who likely had ancestors from the Indian subcontinent. The university staff uploaded its profile to CODIS, the national DNA database that the FBI established in the late 1990s, but no hits turned up.
Fast forward to May 2019, when persistence and coincidence ran headlong into each other, changing the course of the investigation. The occasion was the annual Ohio State Coroners Association meeting. Dr. John Ellis, who by that time had succeeded Dr. Geron as Pickaway County coroner, happened to hear a presentation about unidentified remains by BCI’s DNA lab manager, Kristen Slaper. Afterward, he caught up with her and BCI Criminal Intelligence Analyst Jennifer Lester and told them about the box of bones in his evidence locker. He described it as his office’s “unicorn case” — mysterious and elusive.
DNA technology had advanced exponentially by this time, and Slaper’s first priority was to attempt to extract a large enough sample from the bones so it could be sent to a specialized lab for further testing. Lester, meanwhile, supported the Pickaway County sheriff’s and coroner’s offices, making sure the case was included in BCI’s Project LINK, dedicated to finding missing persons.
“Bone is a very hard substance to get DNA out of,” Slaper said. “The cells are flattened. There’s a lot of calcium. And as the bones become porous and dry out, the DNA degrades. That was the state these bones were in.”
Slaper’s lab processed some of the bones but did not get a profile. After discussion with various forensic scientists, another section of the BCI Lab — the unit that does massively parallel sequencing of DNA — worked on the remains.
“They took the bones, created some bone dust for us and we extracted a couple of more samples. We still didn’t have a great amount of DNA, but there was enough sample to send out for advanced testing to a lab that specializes in working with limited amounts of DNA.”
In this case, advanced testing meant whole genome sequencing, a process that would map all 3 billion pieces of John Doe’s genetic code, something BCI couldn’t do in-house. So the Pickaway County team and BCI turned to a company called HudsonAlpha.
Not long after, in 2021, Lt. Johnathan Strawser, the new commander of the Pickaway County Sheriff’s Office detective bureau, met with Coroner Ellis to revisit the case. Neither man was involved when the case began in 1991 (Strawser was 10 years old), but their predecessors had hammered home their desire to solve it.
With HudsonAlpha having sequenced the victim’s full genome, they decided to pursue another avenue to identify the remains: genetic genealogy, a fairly new technique first used in 2018 to convict the Golden State Killer, a California rapist and murderer. At its core, genetic genealogy is simple — build an enormous family tree — but the process is painstaking.
Experts compare a DNA profile from John Doe to DNA profiles that have been uploaded by private citizens and are available on various databases. The more DNA segments that any two people have in common, generally, the more closely related they are to each other. From there, the process involves a massive search of public records to determine how everybody is related.
Such an investigative tactic would have been impossible before the rise of companies such as Ancestry and 23andMe, and before the popularity of consumer DNA testing in general.
After consulting with Slaper and other BCI forensic scientists, the Pickaway County officials contracted with Amanda Reno at AdvanceDNA, a company that BCI had worked with in the past.
Using the profile provided by HudsonAlpha — a data file that can consist of up to a million lines of code — Reno uploaded the information to GEDmatch and FamilyTreeDNA for comparison. Each of these companies offers a central database where people who have tested at Ancestry or 23andMe or a similar consumer-testing company can upload their DNA profile for comparison against others who have done the same.
Equally important, GEDmatch and FamilyTreeDNA allow law enforcement agencies to upload samples from violent crimes or for unidentified decedents. Other companies do not. Between the two companies, nearly 2 million people have given permission for law enforcement to check samples against their profiles.
Each site provided a long list of matches — some “matches” amounting to only a single tiny segment of common DNA. Reno winnowed the list to the 40 DNA profiles that seemed most relevant, the closest possible relative being a third cousin. From there, she started to build out a family tree for each of the individuals to see how the branches connected. After nine months of work, she was looking at 4,000 names.
“You have to plot every single person,” Reno said. “Every person matters, because if one person is missing, it could be the person we’re trying to identify. So we have to painstakingly go through and validate thousands of records, some of which are hundreds of years old — obituaries, census records, court files, all types of public records that might help us connect our matches.
“Our research stretched into Virginia, Kentucky, Canada and all the way to England. Eventually, we were able to develop a specific profile for our unidentified individual. We needed a father with deep roots in the Appalachian region of Virginia and a mother with immediate connections to England and India.”
Reno contacted eight of the distant relatives; each volunteered additional family information, and some volunteered to share access to their results at Ancestry and 23andMe. Through one of these matches, Reno made a discovery: Deep in the DNA match list was a man named Christopher Mullins Jr. from central Ohio. She clicked on his name for more information and uncovered her best lead: Christopher listed his paternal grandmother’s birthplace as India.
Soon after, in November, Lt. Strawser and Reno met with Christopher Mullins and one of his uncles, David Mullins, who had moved back to Columbus and was living with his nephew. They learned that Christopher — about six year earlier, shortly after the birth of one of his children — had had his DNA analyzed through 23andMe. He quickly agreed to upload his 23andMe profile to GEDmatch for comparison. Within minutes, Reno was able to tell him that he was a nephew of the man whom law enforcement had been trying to identify for 31 years.
John Doe had his name back: Robert Mullins.
All the pieces fit. David’s mother and Christopher’s grandmother, Catherine, had been born in India to an Indian mother and a British father. When Catherine’s father died, her mother moved the family from India to England, where Catherine married a U.S. service member. The young man from the Appalachian hills of Virginia later deserted the family before Robert, the youngest of six kids, even had a chance to know him.
Ultimately, DNA provided by David Mullins confirmed that the remains were those of his little brother.
“What a tragedy to die unknown, to not have a name to put on a memorial,” Ohio Attorney General Dave Yost said. “Thanks to the teamwork and persistence of two generations of investigators, coroners and forensic scientists over the course of three decades, the mystery has been solved for Robert Mullins and his family. The fact of the matter is, a cold case is not a closed case. Now we can get on with the work of finding out who did this to him.”
The case remains an open homicide investigation with the Pickaway County Sheriff’s Office.
Sheriff Matthew Hafey, who has been in office for two years, said the dedication of his team reflects the attitude that his predecessor, Sheriff Dwight Radcliff, brought to the case: “We don’t give up.”
The power of genetic genealogy
Law enforcement uses genetic genealogy to identify anonymous remains and to solve violent criminal cases in which an unknown suspect has left DNA.
The process is twofold. First, it involves taking a DNA extract through a specialized type of DNA testing, either developing what is called a SNP panel or doing whole genome sequencing. Second, it involves comparing that specialized DNA profile to samples from millions of consumers who have made their DNA information available to GEDmatch and FamilyTreeDNA and permitted law enforcement to see their data.
BCI’s DNA Lab does not conduct the specialized DNA testing for developing a SNP panel in-house. Instead BCI partners with local law enforcement agencies to send samples developed at BCI to external private laboratories. Since 2018, BCI has sent out 34 cases, and 21 of those have been solved. Several other cases are still in progress.