More than 60 percent of Americans who have some amount of European ancestry can now be individually identified using DNA databases—even if they themselves have never submitted their own DNA—because of the popularity of tests offered to tell people about their ancestry.
In a report published Thursday in the peer-reviewed journal Science, a team of researchers noted the use of DNA databases to quickly track down criminals. The abstract of their report states:
“Consumer genomics databases have reached the scale of millions of individuals. Recently, law enforcement authorities have exploited some of these databases to identify suspects via distant familial relatives. Using genomic data of 1.28 million individuals tested with consumer genomics, we investigated the power of this technique. We project that about 60% of the searches for individuals of European-descent will result in a third cousin or closer match, which can allow their identification using demographic identifiers. Moreover, the technique could implicate nearly any US-individual of European-descent in the near future. We demonstrate that the technique can also identify research participants of a public sequencing project. Based on these results, we propose a potential mitigation strategy and policy implications to human subject research.”
Their study found that more than 15 million people have undergone “direct-to-consumer” genetic testing; in 2017, about 7 million of the DNA test kits were sold. The report further states:
“Nearly all major DTC providers use dense genotyping arrays that probe around ~700,000 genomics variants and let participants to download their raw genotype files in a plain text format. This has led to the advent of third-party services, such as DNA.Land and GEDmatch, which allow participants to upload their raw genotype files for further analysis. Nearly all of these services offer to find genetic relatives by locating identity-by-descent (IBD) segments that can indicate a shared ancestor. Finding genetic relatives can accurately link even distant relatives, such as 2nd or 3rd cousins and has led to multiple “success stories” within the genetic genealogy community, such as reunions of adoptees with their biological families.
“In the last few months, law enforcement agencies have started exploiting third-party consumer genomics services to trace suspects by finding their distant genetic relatives. This route to identify individuals, dubbed long-range familial search, has been predicted before and offers a powerful alternative to familial searches in forensic databases, which can only identify close (1st-2nd degree) relatives and is highly regulated. In one notable case, law enforcement used a long-range familial search to trace the Golden State Killer. Investigators generated a genome-wide profile of the perpetrator from a crime scene sample and uploaded the profile to GEDmatch ~1 million DNA profiles. The GEDmatch search identified a 3rd-degree cousin. Extensive genealogical data traced the identity of the perpetrator, which was confirmed by a standard DNA test. Between April to August 2018, at least 13 cases were reportedly solved by long range familial searches. Most of these investigations focused on cold cases, for which decades of investigation failed to identify the offender. Nonetheless, one case involved a crime from April 2018, suggesting that some law enforcement agencies have incorporated long-range familial DNA searches into active investigations. Parabon Nanolabs, a forensic DNA company, have announced that they set up a division that will use long-range familial searches and have already uploaded 100 cold cases to third-party DTC services. All of these suggest that long-range familial searches may become a standard investigative tool.”
The use of this technology to solve felony crimes that have eluded investigators for years or even decades is a clear benefit. But at what point does it begin to encroach upon the rights of otherwise law-abiding citizens?
That’s an area the researchers touched on briefly, but concluded it need much deeper study. But, the publication of the report shines light on the fact that law enforcement has already been gaining access to private civilian DNA databases to look for potential matches.