In mid-December, when Colorado Springs detectives identified Ricky Severt as the person responsible for the 1999 murder of Jennifer Watkins, whose body was found under a staircase leading to the helicopter pad at the local hospital, it marked the 50th time in 2020 that a lead from Snapshot DNA analysis team at Parabon NanoLabs resulted in a positive identification. The news followed a flurry of other arrests and positive identifications by Parabon's law enforcement customers in the last months of the year – seven within a 10-day period in November – allowing the Snapshot DNA Analysis Team to close out another successful year of crime solving.
"Finally, some good news out of 2020," said Ellen Greytak, Director of Bioinformatics at Parabon. "We helped identify 50 perpetrators and victims of violent crimes this year, primarily using tiny, decades-old DNA samples. Every day, our team learns something new about successfully working with difficult data or distant matches, and I'm looking forward to an even better 2021."
Colorado police brought the Watkins case to Parabon in 2018, at which time, using DNA from the crime scene, the Snapshot team performed DNA phenotyping and ancestry analysis. Police released the resulting composite to the public in June of that year. A month earlier, Parabon began offering its Snapshot Genetic Genealogy Service and Colorado Springs Police Department asked Parabon to employ the new methods on the Watkins case. Although the analysis was extremely difficult, Parabon's genetic genealogy team eventually generated leads that allowed police to identify Severt.
"We would not be here today if it weren't for Parabon," said Colorado Springs Police Sgt. Kory Dabb in an interview with Denver7 News.
Since introducing genetic genealogy, Parabon has assisted law enforcement in making a positive identification (perpetrator or unidentified decedent) at the astonishing rate of one per week on cases that, on average, have been cold for over 25 years.
"It's remarkable and commendable that the detectives and agencies we serve were able to continue their work largely unaffected by the pandemic," said CeCe Moore, Parabon's Chief Genetic Genealogist. She noted, "Of course, our bioinformatics and investigative work can all be done on a computer, but the agencies had to work our leads using traditional investigative methods and do so despite COVID. Presuming pandemic conditions improve with vaccination, we anticipate even better numbers in 2021."
Parabon Snapshot By The Numbers
| | In 2020 | Overall |
|---|
| Total number of leads resulting in identifications (IDs) (GG+Phenotyping)1 |
50 |
155 |
| Average number of IDs per week since May 2018 |
0.96 |
1.04 |
| Yearsof investigation closed2 |
1,318.7 |
3,640.8 |
| Oldest case closed |
47 years cold |
52 years cold |
| Most recent case closed |
2 years |
3 weeks |
| Average number of years cold |
26.4 |
25.8 |
| Smallest DNA quantity analyzed |
1.015 ng |
1 ng |
| Highest mixture proportion deconvoluted 3 |
60% suspect |
40% suspect |
| Lowest genotyping call rate4 resulting in an ID |
63.4% |
53.5% |
| Most distant top match5 resulting in an ID |
66.2 cM |
61.8 cM |
| Number of US states worked in (+DC) |
45 |
50
|
[1] DNA samples where Parabon provided a lead through one or more Snapshot analyses, and that lead led the agency to an individual whose identity was confirmed through an STR match.
[2] Years between date of crime and date of ID, summed over all IDs
[3] DNA sample contained both the suspect and a known contributor (usually the victim); known contributor's data was bioinformatically subtracted to generate the genomic profile used for analysis.
[4] Percentage of SNPs on the CytoSNP-850K microarray chip with called genotypes
[5] Closest match used in GG analysis; 66.2 cM ≈ 8th degree relative (3rd cousin once removed)
Republished courtesy of Parabon Nanolabs. Photo credit: Parabon.