Can the Fourth Amendment Save Us from the Coming Era of Pervasive Biometric Surveillance?

New technologies mean new crimesolving techniques—and new threats to privacy and liberty.


More and more, police have been using "biometric" technologies—facial recognition, DNA matching, forensic genetic genealogy, and other techniques that are supposed to discern and verify people's personal identities. As civil libertarians worry about such identification techniques' effects on our constitutional rights, the techniques themselves are improving, the databases are getting larger, and the technologies are starting to converge. (It will soon be possible to match faces to DNA found at crime scenes.) What limits do we need to put on how the police use these new powers?

Courts have ruled that the cops can compel arrestees to submit to fingerprinting and DNA cheek swabbing. These data are matched with profiles cataloged in growing biometric databases. The FBI's Integrated Automated Fingerprint Identification System contains fingerprint records from more than 70 million accused or convicted criminals, plus 31 million non-criminal fingerprint records such as those of federal employees. And the agency's National DNA Index contains nearly 14 million offender genetic profiles, 3.5 million arrestee profiles, and 1 million forensic profiles as of April 2019.

Forensic genetic genealogy is the latest way for police to use biometric information to identify persons of interest. Paragon Nanolabs, one of the leading commercial practitioners of this art, defines the field as a "combination of genetic analysis with traditional historical and genealogical research to study family history." It works by comparing a DNA sample from a crime scene with database of DNA from volunteer participants to determine whether the source of the sample has any relatives in the database and how closely related they are. Genealogists then cross-reference those data with traditional genealogical sources, such as census records, birth and death certificates, and so forth.

Forensic genetic genealogy first gained wide public attention last year, when California police used it to trace, identify, and arrest Joseph James DeAngelo. DeAngelo is alleged to be the so-called Golden State Killer, who committed a series of rapes and murders in the 1970s and 1980s. Since that case, police across the country have resorted to the technique to identify suspects in scores of once-moribund criminal cases.

Some 26 million Americans have taken direct-to-consumer genetic tests to find out more about our health and our ancestry. For example, 23andMe tells me that I have 1,216 genetic relatives, including two first cousins of whom I know nothing. Furthermore, I have posted my genetic test information in public where anyone can take a look. So any of my relatives tempted by a life of crime should really reconsider that path.

Police in the Golden State Killer case used genetic information made publicly available by users of the GEDmatch service. The cops collected DNA from crime scenes and submitted the genetic test results to GEDmatch, hoping to identify his distant relatives. Connecting the family trees pointed to DeAngelo as a suspect. Police then collected his DNA from discarded items, which were found to match the crime scene DNA.

In the wake of the Golden State Killer case, many of the genetic genealogy companies worried that clients would become reluctant to use their services and changed their police access policies. At GEDmatch, for example, users are now required to affirmatively opt in to let law enforcement see their genetic test results and relative matches.

No limits so far have been set on how, when, and where police may use forensic genetic genealogy. Jesse Bjerke, who is accused of rape in Virginia, has been identified as a suspect by means of forensic genetic genealogy. His attorneys argue that the DNA evidence should be thrown out because the police violated his privacy rights by surreptitiously collecting his DNA without a warrant. They argue that a warrant is required because Bjerke did not knowingly expose his DNA to public view.

In that case, police submitted DNA collected from two rapes to Parabon Nanolabs, which matched it to users of a genetic ancestry tracing site, who turned out to be Bjerke's cousins. Police then monitored Bjerke and eventually obtained his DNA from discarded beer cans and straws. This evidently matched DNA found at the crime scene. Among other things, Bjerke's attorneys argue that Bjerke did not knowingly expose his DNA to public view by leaving his DNA in public.

Many courts have ruled, citing cases involving photographs and fingerprints, that the Fourth Amendment does not give us a reasonable expectation that the police will not pick up any stray DNA that we happen to leave in public. Some scholars argue that loading suspect DNA into open-source public databases violates innocent relatives' right to privacy in their own genetic data. On the other hand, those relatives have already exposed their genetic test results by uploading them into public databases themselves. (A November 2018 study in Science calculated that so many white people have uploaded their DNA test results that soon 90 percent of Americans of European descent will be identifiable from DNA through genealogy sites.)

While we're working out that constitutional tangle, facial recognition is presenting us with yet another set of questions. This technology works by scanning photos or videos to create face prints based on the unique geometry of individuals' facial landmarks. The face prints are distilled to a mathematical formula that police then compare to a database of known faces. At a recent congressional hearing, the FBI acknowledged it has access to more than 640 million headshots. Courts have ruled that people in public can be photographed without their permission because they have no reasonable expectation of privacy.

In a recent New York Times op-ed, New York Police Commissioner James O'Neill argues that police use of facial recognition makes us safer. The technology, he notes, matches photos or videos collected at crime scenes with a database consisting solely of arrest photos.

Using face prints in that way does seem little different from using fingerprints to identify criminal suspects. But civil libertarians fear that the technology will not stop there. As the Chinese social credit scoring scheme shows, facial recognition technology can be deployed as a real-time mass surveillance system. Each of us leaves lots of DNA and fingerprints in our wakes, but those biometric data exhausts do not enable real-time surveillance. Such concerns have led some jurisdictions to ban police use of the technology for now.

Now genetic and facial recognition biometrics are beginning to converge. A new study in Nature Communications reports that a team of researchers is trying to combine genetic identification with facial recognition. Under this system, police who have a DNA crime sample that does not match any genetic database profiles would check it against a database of faces. Instead of going from DNA to face, researchers go from face to DNA: Special software measures each face and checks whether any is a possible outcome based on the crime-scene DNA sample left by an unknown person.

Parabon currently offers a converse service: DNA phenotyping that translates genetic information from an unknown individual's DNA sample into predictions of ancestry and physical appearance traits, such as skin color, hair color, eye color, freckling, and even face morphology. While not identifying specific individuals, this process can exclude suspects and provide additional leads. It is not too farfetched to imagine police feeding such DNA-derived faces into real-time facial recognition surveillance systems in hopes of identifying and apprehending suspects on the streets. In the future, eyewitness police sketches could be superseded by rapid DNA scans inputted into facial phenotyping algorithms.

Biometric identification contains an inherent tradeoff. Right now, police generally cannot compel you to identify yourself or show identification in public without a reasonable suspicion to believe you're involved in illegal activity. Adopting ever more effective and overlapping biometric identification technologies will amount to the moral equivalent of compelling citizens to carry ID cards and show them on demand to law enforcement agents. And while that's good to the extent that it's used to identify, catch, and gather evidence against rapists and killers, it can obviously be abused as well.

So what must be done? A bill in California would ban police use of realtime facial recognition technology; that seems a good first step. Although the court precedents for fingerprint evidence are not promising, legislatures should perhaps pass laws requiring police to obtain warrants to access other types of our biometric data exhaust, such as DNA in shed skin cells. In any case, when police use these biometric identification technologies, their actions must be made transparent and subject to audit by outside public interest groups.

Back in 2014, when the biggest civil libertarian concern was the revelation that federal spy agencies were secretly keeping track of our telephone conversations, the Privacy and Civil Liberties Oversight Board warned that this information could "be misused to harass, blackmail, or intimidate, or to single out for scrutiny particular individuals or groups." The "danger of abuse may seem remote," the board noted, but "given historical abuse of personal information by the government during the twentieth century, the risk is more than merely theoretical." That same warning applies at least as strongly to biometric policing.

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  1. No.

  2. 2005 wants its query back.

  3. The Fourth has been so steadily whittled away that it’s really only more of a one-fourth by now. I mean, cops can pretty much do whatever the fuck they want and as long as they swear to God they were ignorant of the law and that they were acting in good faith, the courts will give them a pass.

    1. I was following procedure!

  4. One approach to establish the identity of unidentified biological material is to predict the face from DNA, and subsequently to match against facial images. However, DNA phenotyping of the human face remains challenging. Here, another proof of concept to biometric authentication is established by using multiple face-to-DNA classifiers, each classifying given faces by a DNA-encoded aspect (sex, genomic background, individual genetic loci), or by a DNA-inferred aspect (BMI, age).

    I’m guessing this is going to be a long stretch for some time to come.

    Having said that, they were using this technique in the show Quincy by recreating the face of a dead person on a found skull.

    But the above strongly suggests huge guess-factors will be in play.

  5. I am rather skeptical of the technique of face/DNA matching, and whether it will end up being like other forensic techniques (one was reported on in Reason, but I forget what it was) that turned out to be largely pseudoscience.

    This one kind of reminds me of GWAS, which has all sorts of problems. I didn’t RTFA that was linked though, so maybe these concerns are addressed.

    1. *wonder whether

    2. that turned out to be largely pseudoscience.

      If you read a little bit of the paper linked in the article, I think pseudo-science might be a strong word, but it’s likely going to be a science padded with a metric ton of guesswork.

      With dna, you can tell the sex, the ethnicity and something called “individual loci”. Then age and BMI have to be “inferred”.

      At that point you could probably get a face built on ‘average features’ based upon that dna profile: Mediterranean males with a smattering of Arab or Semetic genes look kind of like this– then you produce a series of faces that… yeah, are going to look like average Mediterranean males who have some middle-eastern blood in the family. Probably not seriously useful. Essentially, you’re averaging a series of averaged datapoints which will leave a lot to interpretation.

      1. With dna, you can tell the sex, the ethnicity and something called “individual loci”.

        Not any more. All DNA evidence will be thrown out, as it can no longer even determine the sex of a suspect. Females are DNA identified as male, and males are DNA identified as female. No one can trust that bullshit any longer.

      2. But! If you’ve already got someone you want to pin the crime on then its the new ‘bitemark evidence’.

        1. “Bitemark” was my nickname in Jr Varsity wrestling.

          1. ” Jr Varsity wrestling.”

            And what is that your nickname for?

      3. Yeah, I don’t think that the paper is necessarily pseudoscience (downthread there’s a mention of “bitemarks” which is what I was thinking of), I am just very wary of machine learning based approaches here.

        Essentially, you’re averaging a series of averaged datapoints which will leave a lot to interpretation.

        Right. So I think there’s a lot of potential for overfitting, adversarial examples, etc. Those sorts of things are never reported in overhyped ML/AI press releases, so I fear the public would accept this as totally perfect and “scientific.”

  6. It is fundamentally true that when you are out in public, you have no reasonable expectation of privacy. For example people have the freedom to take your picture. It doesn’t take anything away from you. (Except of course, your soul).
    And as far as facial recognition, is it truly akin to being forced to carry your ID? Or is it the same as wanted posters, just 1000s of times more efficient? What is the fundamental principle involved with not having to carry ID when we are walking around? is it “privacy”? Or is it that we don’t believe police should be randomly rousting people. Using facial recognition allows the police specifically NOT to randomly assault people. Isn’t that a good thing?

    1. Your arguments seem perfectly reasonable to me. But the 4th is particularly susceptible to the slippery slope crested by reasonable laws. And as the masses (both left and right) would agree: The only ones to fear such laws are the criminals with something to hide.

      1. Your arguments seem perfectly reasonable to me. But the 4th is particularly susceptible to the slippery slope

        WTF, dude? I stop reading when a troll uses the common name of a class of logical fallacy as their actual argument. If you are not even attempting to obfuscate your lack of knowledge, why should I bother reading it through.

        Trolls gotta troll, I guess…

        1. I didn’t really follow the slippery slope to a ridiculous conclusion though. But your ad hominem while pointing out my logical fallacy is rich. (As is my tu quoque, I must admit).

          Oh and fuck off.

    2. The privacy exemption for public space has not included a book about your private life attached via databases. Nor has it included a requirement for self identification.

      Perhaps a different way of looking at is asking if autonomy should exist in a free nation. That doesn’t mean you have a right not to be seen in public, but the government does not have a right to demand your papers just because you are on the street.

    3. Point of order, in America you are not forced to carry your ID.

      1. Not yet…socialism…fascism…communism on there way.

    4. What is the fundamental principle involved with not having to carry ID when we are walking around?

      That you have a basic right to exist that doesn’t have to be proven on demand to a government agent.

  7. Of course not.
    The Fourth Amendment haven’t been able to save us from the decidedly lower tech surveillance that we have now. How could it save us from high-tech panopticon dystopia?

  8. The distinction between public and private space may become even more important as surveillance technology improves and becomes less expensive, but our improved ability to monitor and confirm what witnesses have always been able to see in public spaces doesn’t mean that public spaces were ever properly under the protection of the Fourth Amendment. I’m not sure the Fourth Amendment was ever supposed to protect public spaces from technology.

    In the summer, I usually zig-zag my way back and forth across the Sierras for days, with the speeds through some of those empty roads that go far beyond anything the law will allow. It’s one of the great joys in my life. If they bothered to track me on satellite, I suppose it would ruin my fun, and if and when that happens, I’ll have to make a tough choice about whether to suffer the legal consequences or give up on something that, just by itself, made life worth living.

    I won’t blame the Fourth Amendment for spoiling my fun–not if the real culprit is other people’s hostility to freedom.

    The great thing about not being a utilitarian is that I can easily make qualitative arguments. I want to live live in a world where people are so free that they can choose to do things that might not always have the safest outcome for everybody. If technology makes us safer at the expense of more freedom, then people who have a qualitative preference for more freedom rather than safety might decide they don’t want to go that route–regardless of whether the Fourth Amendment is involved.

    1. I very much tend to agree. I would also tend to agree that I enjoy driving on the highway much faster than law enforcement would like (as well as many of my more boring fellow citizens). But, it isn’t a 4th Amendment issue of whether or not I am speeding. Of course I am speeding. Whether or not there should be speed limits, and if so, what is appropriate are valid questions for local and state governments. But since it is on public roads, it is hardly a constitutional question.

    2. ack, I meant to reply to Ken but missed. I ask a question about calculating utility below.

  9. Meh.

    Folks can argue and debate over the merits of police using such databases and techniques, but it’s all gonna be moot when some advertising company figures out how to do that Minority Report trick of personalized ads as you walk the streets.

    Simply put, we may have a right to privacy, but we’re gonna sell ourselves out first anyway.

    1. “”but we’re gonna sell ourselves out first anyway.”‘

      Yeah. We are already on that path.

    2. it’s all gonna be moot when some advertising company figures out how to do that Minority Report trick of personalized ads as you walk the streets.

      You don’t have Google and an andriod phone, do you?
      Been there, done that; turned it off. (I think I turned it off)

      1. I do. And your phone is something you can turn off†.

        But a device and settings under your control isn’t where it’s going to stop.
        †Mostly. To really make it stop tracking you, you have to pull the battery. And sometimes open up the case and pull out a second, smaller, battery.

    3. >>>figures out how to do that Minority Report trick of personalized ads as you walk the streets.

      figureS out? your popups aren’t personalized like the rest of ours?

  10. The great thing about not being a utilitarian is that I can easily make qualitative arguments

    I need some help understanding this.

    A quick analogy:

    I have apples and you have oranges. Assuming no other players and similar nutritional value of both, it could be assumed that we would trade apples and oranges at a rate of 1:1. Not really a situation where utility need be invoked.

    Now, assume the same scenario above except add the caveat that I am not fond of apples while you enjoy eating them in equal quantities to oranges. This seems like a utilitarian problem: there is clearly a quantity of apples in excess of the oranges I receive that I am willing to trade, but there is a point at which I will starve if I give up too many.

    My question is: how does utilitarianism even apply to a situation if there is no qualitative distinction involved. I have seen issues discussed as utilitarian where loss of freedom is given no value whatsoever, when, to people like myself, it’s value is nearly limitless.

    I would say that it is better that 1000 guilty men go free rather than one innocent man be convicted. Some would say that is asking too much society and the criminal justice system. A utilitarian argument over the issue is going to go nowhere unless it can be established that personal freedom has value and that that value is very significant. Isn’t that completely qualitative?

    1. I would say that it is better that 1000 guilty men go free rather than one innocent man be convicted. Some would say that is asking too much society and the criminal justice system.

      You could eliminate the justice system and let infinite guilty people go free and never convict a single innocent person. Even at a ratio of 1000:1, that suggests some utility vs. freedom came into play.

      1. that suggests some utility vs. freedom came into play

        Public safety certainly has utility. It’s just that prosecutors and the left seem to be fine with take their guns and lock them at the first accusation. That, along with the victim’s rights bullshit.

        It was interesting to watch the Kavanaugh confirmation. Having gone through what he did may just soften him up to the idea that rules of evidence are more than just a good idea. When standards slide, it will inevitably cost the innocent more than it costs the victims of the guilty.

        1. I would not find 1000:1 to be an acceptable ratio. 2:1, sure. Maybe 5:1. You start getting up to crazy numbers though like 100:1 and it’s kinda WTF. Letting 100 murderers go free will in fact cost more lives than the 1 innocent guys at that point… It sucks for that guy, but it makes sense from a utilitarian perspective.

          Thankfully I don’t think our odds are all that bad in our current system, and with reasonable improvements it would probably be acceptable.

    2. “My question is: how does utilitarianism even apply to a situation if there is no qualitative distinction involved.”

      This has been the Achilles’ heel of utilitarianism since the first utilitarian fell off the truck. There is a qualitative dimension to every choice, and there is no objective way for policy makers, especially, to account for other people’s qualitative preferences–no matter what what they say!

      “It is quite compatible with the principle of utility to recognize the fact, that some kinds of pleasure are more desirable and more valuable than others. It would be absurd that while, in estimating all other things, quality is considered as well as quantity, the estimation of pleasures should be supposed to depend on quantity alone.”

      —-John Stewart Mill

      He clearly sees the vulnerability. I haven’t seen a better defense of utilitarianism against this charge, but it’s unpersuasive, Mr. Mill! As I recall, he goes on to compare the intellectual pleasure one might get from reading Shakespeare to the sort of frenzied joy our friend Bear Odinson might enjoy at an Amon Amarth gig or the pleasure I get from riding my motorcycle full speed through deserted mountains . . . um . . . on my way to the Shakespeare festival in Oregon! That’s the same kind of justification elitists use for telling us that saving the polar bears is more important than your family’s standard of living. You were just gonna waste it all on big TV sets, McMansions and big, gaudy SUVs anyway!

      Even apart from Mr. Mill’s highbrow sensibilities . . .

      Again, my qualitative preferences are such that I’ve been known to compromise my own safety in exchange for things that spark joy. If a policy maker can’t account for a qualitative preference as universal as safety, how could they possibly account for apples and oranges?

      Incidentally, there is an innovative system that accounts for huge groups of qualitative considerations at the individual level. It’s called “a market”. I get to represent my own qualitative preferences in a market. If I’m willing to pay for the insurance, etc. that helps mitigate the downsides of my risky but fun behavior, I can do that in a market! The downside is that in a market, policy makers don’t get much of a say–but that’s the point.

      The fact is that you can’t have policy makers making choices about apples and oranges without them inflicting their own qualitative preferences on the rest of us. Utilitarians have tried like crazy to talk under, around, over, and through that fact, but they’ve never satisfactorily answered the charges as far as I’m concerned. Sometimes I wonder if the real purpose of Malthusians is to make utilitarians look good by way of comparison.

      1. Thanks for the response, Ken. I only went to college on campus for a year before I quit in disgust, so there is a lot of pointless philosophizing that I missed out on since I was busy learning to build roads instead of standing around blocking them during protests.

        I have read J.S.M. and I love his style, which is why it has eluded me why utilitarianism has such a bad rep. I guess I am a sap for ‘highbrow sensibilities’ and a real love of freedom. Although some of it may just be the contrast to Karl Marx and his ‘lowbrow sensibilities’ and hatred of life. Amazing that On Liberty could be written contemporaneously with Das Kapital. It takes a special kind of sickly, alcoholic wife-beater to blame the ills of the entire world on landowners, but Karl was up to the task.

  11. Sci-Fi scenario cumming to a sleaze-box near you:

    Sleaze-box (combination of a Both-Knows-Everything insider at the DNA Sample Vault of FBI-CIA-KGB-Gestapo Government Almighty agency, with ability to steal genetic samples) and pimple-faced garage-or-Mom’s-basement-dwelling genius biohacker, PLUS sleazy gold-digger willing to take the implant)… Steals the DNA of The Donald, or Jeff Bezos, or other rich person… Manufactures clone-baby… Implants it in Gold-Digger’s womb…


    1. The Donald, or Jeff Bezos, or other rich person is now on the hook to support their genetic legacy!!!

      (Maybe this will put the brakes on the nefarious DNA-samples-lusting ways of Our Overlords!)

  12. The Fourth Amendment is deader than George Washington.

    The right of the people to be secure in their persons, houses, papers, and effects,[a] against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

    All the folderol about oath, affirmation and particular description of persons and things to be seized has been replaced by a dog behaving a certain way when sniffing around your car.

  13. The fourth amendment could not save us from asset forfeiture without even charges.
    The fourth amendment could not save us from license plate scanners.
    The fourth amendment could not save us from stingray cell tower fakes.
    Why the hell would anyone expect it to save us from this?

    (OK, I know that it is the courts, not the actual amendment, that has let us down, but the facts remain)

  14. The fifth and fourteenth amendments also might be seen to bear on the question of asset forfeiture, maybe more that the fourth, as “due process” seems more inclusive than warrant issue. However:

    license plate scanners almost always operate in public where an expectation of privacy is effectively nonexistent, and looking in the governments database of the licenses it issued arguably is not a search in the fourth amendment sense;

    Stingrays generally are used by law enforcement as described in a warrant. They, or their equivalent, may be used by others, including especially capable technicians who roll their own, in other ways, many or most of them illegal but none related to the fourth amendment.

    1. “”Stingrays generally are used by law enforcement as described in a warrant.””

      Not so sure about that. They generally have not been mentioned in warrants. There has been cases where prosecutors dropped charges instead of talking about the use of Stingrays in court. The company that makes them requires LEO and such to sign a NDA.

  15. Is privacy worth the lives of children?

    The Democratic leadership makes similar arguments about guns.

  16. Make the government adhere to the NAP and it won’t matter. Crazy I know.

  17. “What limits do we need to put on how the police use these new powers?”

    The new technology will eventually work its way into the hands of people who aren’t police, and become ubiquitous. Since when has Reason been in favour of putting limits on technology through laws and regulations?

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  19. This shit is gonna get sketchy… I don’t oppose the pigs using some of this stuff in some situations, but we need to put really reasonable (for citizens!) protections in place to make sure it’s not abused. Like warrants all over the fucking place for doing most of this stuff.

  20. I think we all need to stand against it. ri8?

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