Over the last few days, I’ve run across three stories that deal with two aspects of DNA collection: familial DNA, and DNA mixtures.
(This case was mentioned on Forensics and Law in Focus, a recommended read for all sorts of forensic techniques.)
Of all of the biometrics, DNA has a property that the others don’t: the similarity of DNA between family members. Someone finding my child’s fingerprints won’t necessarily be able to find me, and even someone who finds my child’s face won’t necessarily be able to find me.
But 84 year old Raymand Vannieuwenhoven is on trial for a 1976 murder because of DNA similarities in families.
Vannieuwenhoven is accused in the July 9, 1976, murders of a Green Bay couple who was camping at McClintock Park in the Town of Silver Cliff. David Schuldes, 25, and Ellen Matheys, 24, were shot and killed at the campground….
A DNA profile obtained through evidence was already on file with the State Crime Lab, according to previous testimony….
Baldwin explained how a breakthrough came in 2018 when Parabon Nanolabs of Virginia developed new technology to examine DNA evidence, which could provide certain genetic characteristics of possible suspects through DNA….
On Dec. 21, 2018, Parabon contacted Baldwin and informed him that a possible suspect was found through the DNA testing. He said they gave him a Green Bay-area family—the Vannieuwenhovens—that had four sons and four grandsons who possibly could be a match.
The detectives then had to test the relatives and compare their DNA to the crime scene DNA. But not ALL of the relatives: this was solely used as an investigative lead, and there was no point in testing the grandsons for a 1976 murder. Raymand was one of those whose DNA was collected (by having him lick an envelope to seal it), and the probabilities indicated a match.
Obviously this technique has controversy in some quarters, since the family members who originally provided the DNA had no idea that it would be used to arrest (or, in some cases, exonerate) another family member in this way. But the technique is being used.
By the way, Vannieuwenhoven was found guilty, and the 84 year old may be sentenced to life in prison.
The other story concerns what can be found when a DNA sample is collected. The DNA sample may contain a lot of things, from a lot of people.
With improvements in DNA testing methods, we don’t need much DNA to make a profile and see perhaps if I am a likely contributor to that sample or if you have contributed — even if you never touched the table directly. That level of DNA profiling is useful for many different types of crimes, but also brings up the issue of relevance. We aren’t explaining how DNA got to a location.
As an example, a single item at a crime scene may include the DNA of the person who committed the crime, the crime victim, an innocent bystander who touched the area in question before the crime was committed, and (if the police officer was careless) the police officer investigating the crime.
Now you have to look at the DNA sample that was collected. With DNA mixtures, this gets tough.
If single-source DNA is like basic arithmetic and a two-person mixture is like algebra, then a complicated mixture is like calculus!
The quotes above are from John Butler of the National Institute of Standards and Technology, who has a concern about how all of the different laboratories interpret DNA mixtures. Ideally, all labs should work together to have a consistent, verifiable way to interpret these mixtures.
We wanted to see if there were established methodologies that worked better than others when tested, and where those limits were being drawn. What we found is that there is not enough publicly available data to enable an external and independent assessment of the degree of reliability of DNA mixture interpretation practices.
NIST, as it does in other areas, seeks to advance the science, and is urging stakeholders to work together to do so.
But wait; there’s more on DNA mixtures!
While NIST has been conducting the work above, the National Institute of Justice have been funding other work.
Michael Marciano, research assistant professor and director for research in the Forensic and National Security Sciences Institute (FNSSI) within the College of Arts and Sciences, and Jonathan Adelman, research assistant professor in FNSSI, have invented a novel hybrid machine learning approach (MLA) to mixture analysis (U.S. patent number 10,957,421). Their method combines the strengths of current computational and expert analysis approaches with those in data mining and artificial intelligence.
Marciano and Adelman received funding from the National Institute of Justice to further develop their idea in 2014. Although this intellectual property has not been fully developed for commercial use, they are pursuing funding to transition the technology. Once this is done, they are hopeful that the new method will be used throughout the law enforcement and criminal justice communities, specifically by forensic DNA scientists and the legal community.
Actually, once the intellectual property has been developed for commercial use, it will NOT be used THROUGHOUT the law enforcement and criminal justice communities. It will be used by PORTIONS of the law enforcement and criminal justice communities, while OTHERS within the community will use commercial products from competitors.
Commercialization of a product actually works AGAINST universal acceptance, except in very limited cases. Take commercialization of fingerprinting products. As Chapter 6 of The Fingerprint Sourcebook details, independent research was performed in four separate countries (France, Japan, the UK, and the US) which, after commercialization, led to three (now two) separate fingerprinting products: NEC’s product from Japanese research, and IDEMIA’s product from separate French (Morpho) and United States (Printrak) research. This initial research, combined with subsequent research that led to additional products, led to an interoperability issue, despite efforts from NIST to advance greater inoperability.
Will NIST have to do the same thing to reconcile competing DNA mixture analysis methods?