Geneticists, let’s talk about forensic genetics at the US border


The Trump administration has proposed legislation that would make it legal to forcibly collect DNA from hundreds of thousands of migrants held in detention centers at the US-Mexico border [1,2]. This type of mass genetic surveillance is unprecedented. The closest comparison we have for it is the routine screening of newborns for genetic disorders. Most don’t know that DNA samples are obtained from nearly everyone born in the US. Blood is collected at birth, sent off to state laboratories, and then subsequently screened for a host of genetic disorders, many of which neither parents nor most physicians know exist (e.g., very long-chain acyl-CoA dehydrogenase deficiency).

However, unlike with newborn screening, whereby sick babies may directly benefit from the knowledge gained from their DNA, the vast majority of migrants will receive no benefit. Foreseeably, there will be considerable harm. Migrants’ genetic information will be fed into the FBI’s Combined DNA Index System (CODIS) database, which is used forensically in criminal investigations to link serial violent crimes with known offenders. This new influx of DNA samples will saturate CODIS with DNA data from Latino populations and is a stark break from the US’s current policy of collecting DNA from those who are arrested for a crime. 

Given that the proposed policy casts migrants as would-be criminals, the genetics community has a duty to discuss how the US government plans to use our field’s staple technology. By “genetics community” I mean researchers and practitioners with expertise in various aspects of genetics, but also those with expertise in human behavior, epidemiology, bioethics, law, and more. The burden falls on us to offer our knowledge and insights into the ramifications of the Justice Department’s proposed policy, before we enact legislation that stomps out avenues for addressing serious concerns. Because I’m calling for discussion, I’ll start. I am a public-health geneticist (my area of genetics is interdisciplinary and includes ethics) and an epidemiologist and can speak here to some harms involved in collecting genetic data on hundreds of thousands of people. But I am but one person.

Forensic geneticists can better speak to the accuracy of the genetics behind the screening that is planned at the border—that is, they can tell us whether or not the genetic markers chosen for identifying suspected criminals are appropriate and will yield accurate results. But that kind of accuracy is not the only consideration. Human error and interpretation are part of all mass screening programs and contribute to false positives (calling a positive test result “real” when it isn’t) and false negatives (calling a test result “normal” when it isn’t), even when a scientific technique is flawless.

Come back with me to 1995 Los Angeles for an example of the high stakes and pitfalls involved in using genetics forensically: remember the OJ Simpson trial (People of the State of California v. Orenthal James Simpson) [3,4]. Two genetics experts were consulted, one for the defense [5] and one for the prosecution [6]. Both used their expertise to evaluate what genetics revealed about OJ’s role in the murder of his wife. They came, however, to different conclusions about what could be gleaned from the DNA evidence. 

Fast forward to 2007—to Perugia, Italy. Amanda Knox, a 20-year-old American college student living abroad in Italy, was accused of stabbing her UK housemate to death. A speck of DNA evidence on a knife handle from a knife she used for cooking was used to convict her. But that wasn’t the end of the story. Her notorious case turned into a revolving door of conviction and exoneration. She was convicted of the same murder twice before finally being exonerated years later in 2015. The same DNA evidence that was admitted as evidence initially was later deemed invalid by experts [7].

Most Americans find DNA evidence strongly persuasive. A Gallup poll in 2015 showed that 85% of Americans consider DNA evidence to be very or completely convincing [8]. This means that once someone grasps a story linking a person to a crime with DNA, it is hard to consider that the accused may still be innocent. 

Take the case of Lukis Anderson, a homeless man of African-American ancestry who admits he likes to drink alcohol, a lot, and sometimes passes out. Anderson was charged with the murder of Raveesh Kumra, because his DNA was on Kumra’s fingernails. Anderson told his public defender he didn’t remember doing it, but suggested it was possible that he might have but couldn’t remember [9]. That is how persuasive DNA evidence is. 

But the crime was a heinously violent act coordinated by a group of men who broke into Kumra’s home. They blindfolded him, stuffed his mouth with moustache-print duct tape, hit his companion in the mouth, and tied her up next to him. Then they plundered the house and left Kumra to suffocate. Despite Anderson not knowing Kumra and not remembering the event, his DNA was under Kumra’s fingernails, leading investigators to hypothesize that Kumra struggled as Anderson tied him up [9].

Interestingly, other people’s DNA can be found under the fingernails of 1 in 5 people [10]. We can have DNA on us from those we have never met, due to a phenomenon known as “secondary DNA transfer” (e.g., touching a cup someone else touched previously). Secondary DNA transfer may be what happened in Anderson’s case and is an example of a false positive (Anderson’s DNA on Kumra’s nails made Anderson appear guilty, when he was innocent). He could have faced the death penalty had he not had a solid alibi (medical records showing him inebriated and nearly unconscious at a hospital the night of the murder) and a persistent public defender [9].   

Let’s return to newborn screening, another setting where DNA samples require interpretation. Each state in the US has legislation that permits blood to be taken from the heels of newborns born in hospitals. For obvious reasons, infants can’t consent to this procedure. Their blood is used to screen for the presence of certain genetic conditions, some of the more familiar being cystic fibrosis and sickle cell disease. This is a form of large-scale genetic surveillance, which the federal and state governments sanction. Why? Collecting DNA may directly benefit infants suffering from the screened-for genetic conditions, if these conditions are identified and treated before the onset of symptoms. Well-oiled health systems that include feedback from parents and other public stakeholders (e.g., medical experts, lawmakers, and researchers) make this possible. Without newborn genetic screening, many affected infants would suffer irreversible damage and possibly early death. Hence, the US government and each of the state governments have decided to enact these policies because the benefit to affected infants seemingly justifies the lack of consent and the harms of screening nearly everyone born in the US. 

About the harms: By screening the entire population of hospital-born babies, we generate false positives; in this case, laboratory results that incorrectly indicate that a baby has a disease.

Imagine being a parent who gets a phone call saying your baby’s newborn screen is abnormal. You are told she could die. You rush her to the hospital for more tests and you wait, distressed and in an unbearable panic. You can’t eat or think straight. You obsess about high school biology, remembering that genetics are passed from generation to generation. You wonder if you gave your baby the gene. 

Months later, you learn that your daughter’s original genetic sample had been mislabeled. A government worker tells you the hospital where your daughter was born was understaffed. A lot of babies were born that day. One of the overworked nurses had mislabeled the blood sample. This kind of error happens, as do other mishaps: samples can be left on car dashboards and degrade, assays can fail and give misleading information, and sometimes those who interpret results mess up. Other times, having a certain genetic profile never results in the disease it matches with, even when the initial or predictive test results are accurate. 

False positives are inevitable harms of collecting DNA on a large swath of the population. When the testing is done on newborns, healthy children and their families shoulder the burden of this nonconsensual use of DNA. As a society, we have decided that harm to healthy infants and their families is less important than the benefit to those afflicted with a devastating genetic disease. This seems an understandable tradeoff.  

For detained migrants, however, taking their DNA cannot be justified by any such benevolence. Migrants would suffer all the harms inherent to screening programs without any of the benefits. Some of these harms include wrongful conviction, permanently separating families that are biologically related, and compromising migrants’ privacy. Cybersecurity cannot be guaranteed. Enriching CODIS with DNA from migrants places them at disproportionate risk for cybersecurity breaches, possibly leading to a denial of life insurance or employment. Moreover, after harsh treatment at the border, migrants may understandably later recoil from participating in genetic research that could, in fact, directly benefit them, such as efforts to understand breast cancer in Latinas of different ancestries. Stealing DNA at the border could increase migrants’ distrust for science and research at a time when precision medicine has the promise to mitigate disease. It’s unconscionable to let this happen. 

Eventually millions of people will be affected. Last year alone, approximately 743,000 people fell into the category implicated by the proposed legislation. The new rule would remove 28 CFR 28.12(b)(4), the regulation that had previously exempted detained migrants from having their DNA routinely taken [2]. We cannot afford to let the proposed legislation slip into reality without public discussion about the policy implications. Destructive episodes in the history of genetics in the 20th century, such as experiments on prisoners and forced sterilizations of vilified populations [11], make it crucial to talk about the social implications of technologies that target people of a particular ethnic heritage. The proposed legislation treats all detained migrants as if they are criminals and, importantly, as if they will be criminals. Here is a quote from the Federal Registrar about this: “[P]rompt DNA-sample collection could be essential to the detection and solution of crimes [migrants] may have committed or may commit in the United States” [2]. The revealing words here are may commit. This is reminiscent of the dystopian film Minority Report, in which citizens are arrested prior to committing a crime, when a “precog” (someone believed to have trustworthy premonitions) gets a flash of information suggesting a crime may be committed soon [12]. Thus, the proposed legislation is not only about catching individuals that may have already committed crimes. It casts undocumented migrants as likely to commit crimes in the future. If the genetics community doesn’t speak out about this now, it’s passive endorsement. Imagine what future historians of science will say? Will they not link the use of genetics to “build the wall” [13] with the other misuses of genetics in the 20th century? As the saying from Hillel goes, “If I am not for myself, who will be for me? But if I am only for myself, who am I? If not now, when?” [14]. The clock is ticking. 

Aristotle is rumored to have declared, “Poverty is the parent of revolution and crime”. The longer a child remains in poorer circumstances, the higher the risk for violent criminality as a young adult, according to a recent and large population-based study published in Lancet Public Health [15]. The FBI could be justified in claiming that crime happens more often in poorer neighborhoods, since the connection between violent crime and economic disadvantage is well-documented [16]. But imagine the outcry if the newborn screening DNA obtained from newborns living in relatively poor zip codes were given to the FBI for forensic purposes. These innocent newborns, by virtue of their zip codes, are predicted to have a greater chance of possibly committing violent crimes later in their lives than those born into families living in wealthier zip codes. Just as the argument from the US Justice Department justifies collecting DNA from migrants because they might commit crimes in the future, this same argument could someday be levied against the poor who happen to live on this side of the US fence. The road we are headed down by staying silent is dangerous. A nationwide shift in how migrants are viewed is necessary. Migrants must be treated with dignity and receive the protections expected by any person who is not believed to have committed a violent crime. 

Along with the discussion of the dangers inherent in casting groups as would-be criminals, it would be helpful to discuss ethical uses of forensic genetics and how these might be leveraged to do good. Examples of ethical uses of DNA evidence might include those similar to Mary-Claire King’s successes in reuniting separated Argentinian families [17] and the use of genetics to identify victims of human rights violations [18]. It is conceivable that, in a similar way, some migrants could be reunited with children torn from them at the border. But the stated use of the pilot DNA collection program upon which the proposed legislation is partly based is to detect “fraudulent family units”— migrants believed to be posing as families to exploit the system [1]. Thus, I suspect the US government will not use DNA taken from migrants in a way that provides the direct benefit of reuniting families. But it is possible to look into how to do it. I am not, by myself, knowledgeable enough to help in this area, other than to signal its importance.  

From my vantage point as a public-health geneticist, I have offered a few examples of the harms involved in mass genetic screening, including errors and racial profiling. If DNA is going to be taken forcibly, striving to ensure there is some benefit to our migrants is the least we can do given the power we hold and the ethical responsibility we have to other human beings. Because of our collective knowledge of the science, history, and ethical dimensions of genetics, we — maybe even more than government officials— are responsible for the ways in which our technology is used. Moreover, migrants need to be part of the discussion to find out what would be helpful to them and how they hope their DNA could be used, should the legislation be enacted. Those with skills in starting and maintaining community dialogue are needed here. 

In addition to our technical expertise and knowledge of history, the genetics community includes people of varying political persuasions, representing a range of opinions regarding how to handle migration. We should talk. But whatever your politics, using genetics to racially police society is both unnecessary and unethical. 

I hope we can pool our resources to talk about the legislation and act to protect the humanity and futures of those fighting to be in the United States.

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