In the fall of 1989, a small group of forensic scientists, law enforcement officials and representatives from Promega Corporation gathered in Madison, Wisconsin, for the very first International Symposium on Human Identification (ISHI). At the time, DNA typing was in its infancy and had not yet been validated as a forensic method. The available technology consisted of two methods: detection of restriction fragment length polymorphisms (RFLPs) and variable number of tandem repeats (VNTRs). Promega had developed products based on both analytical methods, which essentially provide a DNA “fingerprint” or profile for each individual tested.
Written by: Ken DOyle, Promega
Among the attendees at that first symposium was Tom Callaghan, then a graduate student. That experience made a significant impact on his career path. Last week, at ISHI 30, he presented a session on rapid DNA testing. Dr. Callaghan currently serves as a Senior Biometric Scientist for the FBI. In 1999, he was instrumental in launching the FBI’s Combined DNA Index System (CODIS) and in 2003, he became the first CODIS Unit Chief.
ISHI 30 opened with a video offering a tongue-in-cheek look back in time at how technology—in general and in the field of forensics—has changed, from DNA sequencing gels to landline phones to fax machines. The video featured Dr. Cecelia Crouse, who left behind an academic career to work in forensics. Last year, she retired from the Palm Beach County Sheriff’s Office, Florida, after nearly three decades of using DNA analysis to solve crimes.
Following Dr. Crouse, Bill Linton, CEO of Promega Corporation, welcomed the ISHI 30 attendees. He reflected on the growth that ISHI has seen over the past 30 years and the overwhelmingly positive response from the forensics community. He outlined his vision for the symposium and recalled seeing its global potential from the very beginning with that first meeting in Madison. (Read an interview with Bill on the past, present and future of ISHI in the April 2019 issue of The ISHI Report.)
The keynote address at ISHI 30 was delivered by Paul Holes, retired Chief of Forensics with the Contra Costa County District Attorney’s Office, California. Holes relates the chilling story of the case that dogged him for over 20 years—the notorious Golden State Killer, who committed over 100 burglaries, more than 50 rapes and at least 13 murders from 1974 to 1986. Ultimately, Holes solved the case in collaboration with a genetic genealogist, using the relatively new—and controversial—technique of forensic genetic genealogy (FGG) or investigative genetic genealogy. (Read the complete story in the April 2019 issue of The ISHI Report.)
Technology and the Human Factor
Although genetic genealogy itself is not new, the use of genealogy databases by law enforcement has attracted recent attention, spurred on by cases like that of the Golden State Killer. Holes emphasized that investigators never have access to an individual’s DNA profile in the database; rather, they are simply examining how much DNA is shared by people in the database and the suspect. Nonetheless, due to public concerns about how the information may be used, a popular genealogical database, GEDmatch, recently changed its terms and conditions so that all users would opt out of letting law enforcement access their data by default. As a result, GEDmatch went from having over 1 million profiles accessible to law enforcement to around 120,000 opt-ins as of August 2019. These numbers were cited by several speakers at ISHI 30 as posing a serious challenge to the use of FGG.
The issues of privacy surrounding FGG have prompted a lot of discussion in the forensics community. At ISHI 30, the Department of Justice unveiled its new interim policy for FGG, which spells out specific criteria for cases where the technique should be applied. The policy is seen as an important first step to addressing some of the public’s concerns.
Several other technological trends emerged at ISHI 30. Massively parallel sequencing was featured in many of the posters presented. The technology holds great promise for DNA forensics but it has seen slow adoption in forensic units. The gold standard for DNA forensics still remains the analysis of short tandem repeats (STRs) by PCR amplification with specific probes, followed by capillary electrophoresis. In addition to MPS applications for both mitochondrial DNA sequencing and SNP analysis, the technical presentations at ISHI focused on DNA mixture deconvolution, probabilistic genotyping and rapid DNA testing to identify disaster victims.
It’s easy to get caught up in technological advancements, especially when considering the future of forensics. Sometimes, that can overshadow the underlying reasons driving the technology forward. In a compelling case study presented at ISHI 30, CeCe Moore, a genetic genealogist at Parabon Nanolabs, led the audience through the twists and turns of a case that began with the gruesome rape and murder of 18-year-old Angie Dodge in 1996. Through a combination of FGG and another recent development, genetic phenotyping, a suspect was arrested this year and is currently awaiting trial. Moore’s case study, along with others presented, emphasized the importance of not only serving justice but also giving the victim’s family the closure they sought.
That’s the reason technology will continue to advance, and the reason that Promega will continue to support ISHI year after year. As Linton says:
“The work they do for most of the people who attend is not academic work, it’s not theoretical work, but every day they are involved in using advanced technology with outcomes that touch many, many lives.”
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