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Hit ‘Bear Brook’ podcast carries a scary message – about genetic privacy, not murder

  • One of the barrels containing bodies found near Bear Brook State Park in Allenstown, triggering a decades-long murder investigation.  Courtesy



Monitor staff
Tuesday, November 13, 2018

There are many things to be learned from the wildly popular podcast “Bear Brook” from NHPR, which dissects a decades-long murder investigation in Allenstown, but from my point of view the major (and majorly depressing) takeaway is this:

Big data and cheap DNA tests are destroying our real-world privacy just as effectively as big data and tech companies are destroying our digital privacy. And there’s nothing we can do about it.

Jason Moon, the NHPR reporter who created the six-part podcast, sort of agrees with me, although with less gloom and doom.

“There’s a debate coming in the next several years that we may not be prepared for. People may not even realize it’s coming,” is how he put it when we spoke recently.

“Bear Brook,” which as of this writing has been downloaded a whopping 1.1 million times, is a long piece of true-crime reporting that centers on four bodies – a woman and three children – found in barrels on the edge of Bear Brook State Park in 1985.

The victims were unidentified while their likely killer was unknown for decades. The killer was only found two years ago thanks to a process known as genetic genealogy, which will revolutionize crime forensics even as it shreds our personal privacy.

I won’t go into details about the investigation because it’s much more fun to hear them unfold over the course of the podcast, which you should definitely listen to. The impatient among you can learn everything by reading old Monitor stories from our website.

Instead, let’s concentrate on the science.

Genetic genealogy is the process of analyzing data from thousands or millions of genetic samples to find similarities among people that indicate relationships.

In general, it doesn’t depend on the Y chromosome, the male sex chromosome, which has long been useful for establishing paternity, or the passed-down-through-female-line mitochondrial DNA, which is key to understanding how the human species evolved and spread over the globe.

Genetic genealogy depends on analyzing autosomal DNA, which is all the rest of the genetic material in our cells. Autosomal DNA holds a lot of information – we’re talking about 22 chromosomes – and widespread, real-time analysis only became possible fairly recently with advances in computing and big data.

The other advance that has made genetic genealogy possible are online DNA databases, like 23andMe or Ancestry.com. Millions of people have sent in samples of their saliva to be analyzed and placed it on public or private databases, hoping for enough connections between their autosomal DNA and other people’s autosomal DNA to uncover that they are fifth cousin to Barack Obama or a direct descendant of one of the Salem witches or, more realistically, have nearby relatives they didn’t know about.

What’s this got to do with privacy?

If somebody gets hold of your DNA by, say, grabbing your discarded Dunkin’ cup out of the trash, they can perform genetic genealogy and maybe find relatives you didn’t know you have.

But that’s not the real problem. The real problem is that genetic genealogy can operate in reverse, so to speak. Instead of starting with known DNA and finding relatives, it can take an anonymous DNA sample, find some relatives, and then backtrack from all of them using traditional genealogy methods to identify who the sample came from.

This means that even if you’re a private person who has never handed over your DNA to a private company, your genes can still be used to identify who you are because of all the genetic data that other people have uploaded. You can run, but you can’t hide.

“Whether you want to be or not, we’re all already in the databases to some extent,” said Moon.

This is how one person connected to the Bear Brook case was found as the first use of genetic genealogy for crime forensics. Since then, law enforcement has embraced the idea, pulling old DNA samples out of evidence lockers and using them to solve a number of cold cases, notably the Golden State Killer in California.

There’s no protection against this discovery, either. You and I and every other human being leave behind DNA samples everywhere we go, so The Powers That Be will soon be able to figure out everywhere we’ve been in the real world, just as Google can figure out everywhere we’ve been online.

To use outdated tech terminology, privacy in meatspace will go the way of privacy in cyberspace.

I admit this is a bit of an overstatement, for now. There are technical limits to this process, which is why the Bear Brook victims are still unidentified, and there are some legal and regulatory protections.

But the technical obstacles will be overcome. Moon notes in his podcast that the initial breakthrough in the Bear Brook case took 10,000 hours of work but the same thing can now be done with 10 hours of data crunching.

And legal or regulatory protections always get bypassed if there’s enough of an incentive. If nothing else, bad guys will hack into the genetic-company databases (a rule of modern life: all databases get hacked) to profit from our autosomal abnormalities.

“I didn’t realize how thorny it might turn out to be,” said Moon, who says he knew nothing about genetic genealogy when he started covering this case. “On the one hand, there’s the great promise of what it has done ... It has done a lot of good, given a lot of people closure, put dangerous people behind bars.

“But the question I kept coming back to is: How much are we willing to give up for that outcome?”

(David Brooks can be reached at 369-3313, or dbrooks@cmonitor.com or on Twitter @GraniteGeek.)