opinion | Nathaniel P. Morris

A fingerprint does not contain your genetic code


The power of genetic information has shaped virtually every aspect of medicine. On one hand, we have learned about diseases and treatments that are now defined by patients’ genomes. Certain genes can predict colorectal cancer with near certainty and, in women, the BRCA mutations, famously discussed by Angelina Jolie, can denote a greater than 80 percent risk of developing breast cancer. We can screen newborns for dozens of genetic diseases and immediately know which diets to avoid giving them or which medications to begin early. Physicians are using genetic markers to better tailor therapies to individual patients. We are certainly entering a new era.

Yet, amid these exciting advances, we are constantly reminded of the risks of this brave new world. Genetics is progressing faster than we can understand its consequences and, in the middle of this chaos, ordinary Americans have become subject to technology that we cannot entirely control. Scientists are only beginning to characterize the psychological impacts of receiving a genetic diagnosis that may not manifest itself for years. Most doctors are not trained to handle their patients’ genetic profiles and stumble through conversations filled with anxiety and uncertainty. In a study released in 2011, 71 percent of Americans expressed concern over the privacy of genetic tests.

All of this is to say that, while our discoveries surrounding DNA are changing the world, we can barely grasp the weight of the information at hand. In response, the medical community has opted for diligence and introspection regarding this new frontier. Academic journals churn out papers debating the ethics of these new paradigms, and medical schools have incorporated genetics courses into their curricula. Our foremost experts agree that now is a time for great caution. But, last Monday, the US Supreme Court led our nation down a different path.


In Maryland v. King, the justices heard a case where a man was arrested for assault and swabbed for DNA without consent; this swab was submitted to a national database, through which his genetic profile matched evidence from an unsolved rape. After receiving a life sentence for this earlier crime, he sued under the Fourth Amendment on grounds of warrantless search and seizure. By a 5-4 vote, the court decided against him and ruled that police officers can take DNA swabs from anyone under arrest for “a serious offense.”

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Writing for the majority, Justice Anthony Kennedy held that the primary purpose of these swabs would be to confirm the identity of suspects, not to solve crimes. He reasoned that the benefits of identifying a criminal suspect far outweigh the harms of seizing an individual’s DNA: “Taking and analyzing a cheek swab of the arrestee’s DNA is, like fingerprinting and photographing, a legitimate police booking procedure that is reasonable under the Fourth Amendment.” And he could not be more wrong.

A fingerprint cannot tell you that you are at significant risk for disease. It cannot tell you where your ancestors came from or your prospects for having healthy children. It cannot describe the molecular pathways that contribute to your personality and behaviors. A fingerprint is simply not in any way like DNA.

Highlighting these differences, a number of Kennedy’s critics have relied on the slippery slope argument to attack his claims. In a blistering dissent, Justice Antonin Scalia warned of the creation of “a genetic panopticon.” Senator Ted Cruz of Texas echoed his sentiments, raising fears of DNA sampling aboard airplanes and in public schools.

These ideas are indeed terrifying. But there is something more to the basic notion that we are granting our government access to that which we do not yet understand. We have a great deal to learn about the genetic fabric of our lives. The majority of our genome remains unexplored, and we cannot predict what we will find in the near future. When I think about police swabbing our citizens regardless of their innocence, it is the vast unknowns of our genetic code that scare me most.


We can still use DNA to identify suspects and solve crimes. However, the most precious details of our individual biologies deserve stronger protection than the requirement that police have probable cause for an arrest. The forensic use of genetic information should remain within its existing boundaries of courtrooms and warrants, its rightful place of wary constraint.

Nathaniel P. Morris is a student at Harvard Medical School.