Earlier this week, GTH-DNA revealed the six finalists for the 2023 DNA Hit of the Year, including two U.S. entries—the identification of a burglary ring that escalated to the murder of a member of the U.S. Coast Guard and the identification of a serial killer who terrorized Denver in the 1970s.
The DNA Hit of the Year program, now in its seventh year, is a global program established to demonstrate the power of forensic DNA databases to solve crime and identify missing persons. Every year, GTH-DNA partners with a group of international judges to determine which submitted case will be recognized as the official hit of the year—but this year was different.
At the HIDS Conference on Tuesday, GTH-DNA surprised everyone by revealing all six finalists would be considered the 2023 Hit(s) of the Year.
In addition to recognizing the incredible work forensic scientists and investigators perform, another goal of the DNA Hit of the Year program is to showcase the benefits of a forensic DNA database, when constructed correctly and ethically. This fact was highlighted—even more than in years past—by two specific Hit of the Year cases submitted from outside the United States.
Kingdom of Bahrain
In response to increasing terrorism in her country, a forensic scientist in the Kingdom of Bahrain developed a new methodology to swab IEDs to capture as much DNA as possible. In 2020, Dr. Noora Al Snan was finally able to link the detonation of 34 IEDs from 2015 to 2017 to one man—who was not in the DNA database. This was thanks to a creative application of familial searching and the common in-breeding seen in some populations in Bahrain.
Before 2012, Al Snan was working on robberies and sexual assaults.
“Then, all of a sudden, it was bombs,” she said. “We started working on IEDs, which we were not familiar with at all.”
Al Snan and her team started doing their own research and validation on different types of samples, such as C4, different types of plastics like PVC pipes, and different parts of IEDs, such as the tapes and electronic devices. They decided to change the conventional swabbing system from a single cotton swab to a double cotton swab, even a nylon swab from time to time.
Continuing to research along the way, Al Snan demonstrated that C4 does not inhibit the PCR process—a fundamental piece of knowledge for forensic scientists tasked with analyzing explosive devices.
“Some labs used to skip the DNA recovered from C4 because they were not aware that there’s a lot of efficient findings from samples contaminated with C4 or any other type of explosive material,” said Al Snan.
In 2015, perpetrators in Bahrain began placing real and hoax IEDs in public places. Once first responders and others congregated close to the hoax IED, perpetrators would set off real ones nearby to inflict maximum damage.
For both types of IEDs, we separated the components, wiped the wire, then swabbed the inner areas of the plastic pieces as well as all the remaining plastics. For each IED, we collected up to 30 swabs or samples. Each sample was then handled separately during DNA processing.
Over a two-year period from 2015 to 2017, Al Snan’s lab linked one unknown male DNA profile to 34 IEDs. The DNA was collected from all different parts of the IEDs, including the tape, plastics and cans. But, of course, the unknown male was not in the database—so Al Snan had to find him through different means.
The forensic scientist’s Ph.D. was in population genetics. During that time, she worked with 500+ DNA samples and came to notice something unique—families and people involved in cousin marriages had a lot of homozygous runs in their profiles. Al Snan confirmed this with a volunteer in her lab who was from a third-generation cousin marriage. Samples from her, her father, mother, husband and children showed 9 or 10 loci homozygous.
Interestingly, the unknown DNA profiles from Al Snan’s terrorism cases also had a lot of homozygous runs, including the one linked to the 34 IEDs.
In 2020, Al Snan decided to check the DNA database only for the homozygous and microvariants found in the profile of the unknown male. Incredibly, she got a hit. There was a partial match to a man already in jail for a terrorism act.
“I searched the [jailed] person’s address and there was a brother who did not have his DNA in the database. We asked for a sample, he consented to it, and was immediately linked to all the IEDs,” said Al Snan.
Now, Al Snan’s lab uses the partial match method—or really kinship match method—for all different types of cases, anytime there is an unknown profile from any crime.
“Because of in-breeding and the high number of homozygous it creates in the DNA profile, we can use the homozygous peaks to check the database, instead of searching for the whole DNA profile match,” said Al Snan. “When we search for the whole 24 [loci] GlobalFiler kit, there is no a match.”
South Africa
Almost 10 years ago, South Africa became one the first African country to pass DNA laws and establish a national DNA database program. While the country still has challenges, as apparent in their Hit of the Year case, it has also been an inspiration to so many countries in Africa to follow suit.
“We are starting to see significant interest by so many countries to develop DNA databases through Africa,” said Vanessa Lynch, GTH-DNA’s regional leader for DNA for Africa and senior consultant. “In particular, this growth has been exponential in the last 12 months with multiple African countries positioning themselves to set up DNA databases, such as in Kenya, Zambia, and Somalia to name a few.”
On Oct. 10, 2016, police were called to the scene when citizens found the decomposed body of an unknown female in a wooded area along a roadway. Investigators could not identify the body, but did collect reference DNA samples, fingerprints and a rape kit.
Elsewhere in the country, the mother of 23-year-old Linda Metata filed a missing person’s report at her local police station after her daughter failed to come home from a party. But the investigation was not launched right away. In fact, Linda’s mother did her own recognizance and found out Linda left the party with Thabo Mosia, a known robbery kingpin who had been arrested before, but never convicted.
With that information in hand, police escalated Linda’s case to kidnapping and arrested Mosia as a suspect, collecting a swab from him upon arrest. Mosia eventually confessed to the murder, but only because he did not think Linda’s body had been recovered and therefore police could not make a case against him.
That would have been true if not for Wilhelm Diedrick Fouche, the assistant director of forensic pathology at Bronkhorstsoruit Gauteng Department of Health, who processed the unidentified remains found back in October 2016. By law, Fouche should have given the unidentified remains a pauper’s burial after 30 days, but he didn’t.
“I really felt like [she] had a family,” said Fouche, “a family that was looking for her. I didn’t do the burial request so for 9 months the body was at our mortuary.”
That turned out to be an incredible thing as investigators called Fouche months later to see if they had the body of someone who may be Linda, as the buccal swab taken from Mosia hit to the profile developed from the rape kit taken from the unidentified remains. Another DNA analysis confirmed the remains as Linda, and Gloria as her mother.
The following year, Mosia was sentenced to the rape and murder of Linda.
“This case makes the point that passing laws and implementing criminal offender and crime scene databases is only the beginning to ensuring a national DNA database program is working to full capacity,” said Tim Schellberg, President, GTH-DNA. “What South Africa does with DNA will provide the framework most countries in Africa will follow as they embark on establishing their own programs.”