By Mark J. Becker, CIPP/US, CIPP/G

Using sophisticated techniques, they extract the preserved blood from the mosquito, and, bingo, DinoDNA." Jurassic Park

DNA collection sounds like science fiction, and when it comes to recreating the T-Rex, it remains just that. However, today’s reality is that DNA is collected from those convicted of crimes in all 50 states, while 28 states and the federal government collect DNA from some or all arrestees prior to being tried and convicted.

In a 5-4 decision, the U.S. Supreme Court reversed the Maryland Court of Appeals in June to rule that collecting DNA from custodial arrestees is constitutional. In King v. Maryland, Justice Kennedy, writing for the majority—Chief Justice Roberts, Justices Thomas, Bryer and Alito, holds that collecting DNA by swabbing the inside cheek of an arrestee is a reasonable search under the Fourth Amendment; that is, no different than fingerprinting or photographing an individual during the booking process at the police station.

As will be discussed later, the Justice Scalia-written dissent portends problems with expanded collection of DNA that parallel concerns with the then yet-to-be disclosed bulk collection of phone metadata by the National Security Agency (NSA).

King’s Arrest

In 2009, Alonzo King was arrested for menacing a group of people with a shotgun and charged in state court with assault. A cheek swab was used to take King’s DNA in accordance with the Maryland DNA Collections Act (DNA Act), which requires police to collect DNA from arrestees “charged with a crime of violence or an attempt to commit a crime of violence; or burglary or an attempt to commit burglary.” King’s DNA was uploaded to Maryland’s DNA database, which matched DNA collected from an unsolved 2003 rape case. King was subsequently indicted by a grand jury for the 2003 rape. Law enforcement then secured a search warrant and collected a second DNA sample from King, which again matched the DNA collected six years earlier. After unsuccessfully moving to suppress the DNA evidence as violating his Fourth Amendment right to be free from unreasonable search and seizures, King was convicted of rape and sentenced to life without parole. On appeal, the Maryland Court of Appeals held that collecting DNA from arrestees under the DNA Act was unconstitutional as an unreasonable search under the Fourth Amendment since King’s “expectation of privacy is greater than the state’s purported interest in using his DNA to identify him.”

The Science

In order to understand the centerpiece of this 21st-century century collection, a brief understanding of DNA and the type of DNA collected from arrestees is helpful.

As we all learned in eighth-grade biology, all living things have chromosomes in the nucleus of all cells, which contain DNA. DNA may be collected through saliva, blood, semen, skin or hair samples. DNA is composed of “coding” regions that produce proteins and “non-coding” regions that do not produce proteins. The non-coding regions are used to determine identity and are not known to indicate a genetic propensity or disease. The DNA collected from these non-coding regions is commonly referred to as “junk DNA” for its limited usefulness.

Although DNA code from person to person is about 99.9 percent identical, there are also regions where the DNA code varies, and within these regions are sort tandem repeats (STRs), which are repetitive sections of DNA that vary in number for each person. The size and frequency of the STRs are called “alleles” and are used to ensure the STRs are unique to an individual. In creating a DNA profile, law enforcement compares 13 loci of the STR alleles. The possibility for two unrelated individuals having the same STR alleles in a sample is one in 100 trillion, according to the Institute for Homeland Security Solutions’ “Human DNA Identity Testing Policy Report”.

Context Is King in the Fourth Amendment

The Fourth Amendment, in part, grants “[t]he right of the people to be secure in their persons, houses, papers and effects, against unreasonable searches and seizures…”

In determining the reasonableness of a search, the court looks to whether the individual has a legitimate expectation of privacy in the context of the search. For instance, the court has ruled that “[l]egitimate privacy expectations are even less with regard to student athletes…[p]ublic school locker rooms…are not notable for the privacy they afford.” Similarly, workers in certain types of regulated professions may be subject to certain intrusions that diminish their expectation of privacy, while those same privacy intrusions in another context may be considered unreasonable for purposes of the Fourth Amendment.

Kennedy finds a custodial arrestee, such as King, has a diminished expectation of privacy. However, the court must also weigh the privacy interests of an individual against the government’s interest in determining the reasonableness of the search. When the public interest outweighs an individual’s privacy interests, no warrant is required before conducting the search.

Since not all searches are created equal, a reasonableness inquiry considers not only an individual’s legitimate expectation of privacy, but also the degree of privacy intrusion involved. For instance, the court writes, “[s]ome searches, such as invasive surgery or a search of the arrestee’s home, involve either greater intrusions or higher expectations of privacy than are present in this case.”

According to Kennedy, “[i]n those situations, when the court must ‘balance the privacy-related and law enforcement related concerns to determine if the intrusion was reasonable,’ the privacy-related concerns are weighty enough that the search may require a warrant, notwithstanding the diminished expectations of privacy of the arrestee.”

The majority concludes that swabbing the inside cheek of a custodial arrestee is a reasonable search under the Fourth Amendment, as it is brief and minimally intrusive.

“[A] buccal swab involves…[a] brief and still minimal intrusion. A gentle rub along the inside of the cheek does not break the skin, and it ‘involves virtually no risk, trauma, or pain.’ ‘A crucial factor in analyzing the magnitude of the intrusion…is the extent to which the procedure may threaten the safety or health of the individual’ and nothing suggests that a buccal swab poses any physical danger whatsoever. A…swab of this nature does not increase the indignity already attendant to normal incidents of arrest.”

No Individualized Suspicion Needed

Kennedy also distinguishes between searches based on individualized suspicion and systematic suspicionless searches of the general public—e.g., a drunk-driving checkpoint, also known as “special needs” searches—that are not based on any suspicion of individual wrongdoing. The court has previously held that suspicionless searches must not be conducted in furtherance of “ordinary law enforcement” since those searches lack individualized suspicion.

“When the police stop a motorist at a checkpoint…they intrude upon substantial expectations of privacy. So the court has insisted on some purpose other than ‘to detect evidence of ordinary criminal wrongdoing’ to justify these searches in the absence of individualized suspicion,” Kennedy writes.

The majority, contrary to the dissent, finds that collecting King’s DNA incident to an arrest is a permissible search that does not require individualized suspicion. The majority’s rationale is that an arrestee enjoys a diminished expectation of privacy and his arrest is enough to justify the search of his person and possessions.

“[T]he court has been clear that individual suspicion is not necessary, because ‘[t]he constitutionality of a search incident to an arrest does not depend on whether there is any indication that the person arrested possesses weapons or evidence. The fact of a lawful arrest, standing alone, authorizes a search.’ ”

In particular, the majority notes “DNA identification like that at issue here…does not require consideration of any unique needs that would be required to justify searching the average citizen. [U]nlike the search of a citizen who has not been suspected of a wrong, a detainee has a reduced expectation of privacy.”

Just Another Identification Tool

Kennedy emphasizes the efficacy in identifying not just an arrestee’s name but his criminal history as a regular part of the booking process. DNA collection, according to the court, is yet another tool to help understand more about an arrestee and is consistent with law enforcement’s history of embracing of new technologies to identify arrestees, as they have done for over a century, using photography, Bertillon measurements—10 measurements of the arrestee’s body—and fingerprinting.


Does DNA Collection Reveal Medical Information?

Although the DNA collected and tested by law enforcement is considered “junk DNA” in the sense that it does not reveal genetic predispositions, Kennedy notes that whether this testing “reveals any private medical information at all is open to dispute,” and even if the tests do reveal an arrestee’s current or future health risks, the tests are not performed for that purpose but only for purposes of identification. The majority analogizes DNA testing with school drug testing, which is performed to look for drugs in a student’s system and “not whether the student is, for example, epileptic, pregnant or diabetic.

Kennedy concedes that “[i]f in the future police analyze samples to determine, for instance, an arrestee’s predisposition for a particular disease or other hereditary factors not relevant to identity, that case would present additional privacy concerns not present here.”

Scalia’s Dissent—An Unusual Quartet

In a blistering dissent, Justice Scalia, joined by an unusual quartet of the more liberal-minded Justices Ginsburg, Sotomayor and Kagan, blasts the majority for concluding that DNA is collected for identification and not for law enforcement to solve crimes.

“It is obvious that no such noninvestigative motive exists in this case. The court’s assertion that DNA is being taken, not to solve crimes, but to identify those in the state’s custody, taxes the credulity of the credulous. And the court’s comparison of Maryland’s DNA searches to other techniques, such as fingerprinting, can seem apt only to those who know no more than today’s opinion has chosen to tell them about how those DNA searches actually work.”

DNA Collections Are Suspicionless Searches

Scalia argues that “general warrants,” those warrants that do not articulate individual suspicion, have lacked support in this country going back to British rule.

“The Fourth Amendment forbids searching a person for evidence of a crime when there is no basis for believing the person is guilty of the crime or is in possession of incrimi­nating evidence. That prohibition is categorical and with­out exception; it lies at the very heart of the Fourth Amendment,” Scalia writes. “Whenever this court has allowed a suspicionless search, it has insisted upon a justifying motive apart from the investigation of crime.”

Scalia agrees that suspicionless searches may be permissible if the search does not further the interests of ordinary law enforcement. Random drug testing of railroad employees is permissible, for instance, since the government has an interest in the safety of railroads, which “is distinct from ‘normal law enforcement’.” Similarly, suspicionless searches of public schools are constitutional because the government is fulfilling its “responsibilities…as guardian and tutor of children entrusted to its care” and not to engage in law enforcement.

In contrast to those situations, Scalia argues that collecting DNA from an arrestee to identify his previous crimes is nothing more than a law enforcement activity.


Interestingly, Scalia contends that what King’s DNA “‘identified’ was the previously-taken sample from the earlier crime.”

“King was not identified by his associ­ation with the sample; rather, the sample was identified by its association with King. The court effectively de­stroys its own ‘identification’ theory when it acknowledges that the object of this search was ‘to see what [was] al­ready known about [King]’.”

“No minimally competent speaker of Eng­lish would say, upon noticing a known arrestee’s similarity ‘to a wanted poster of a previously unidentified suspect’ that the arrestee had thereby been identified. It was the previously unidentified suspect who had been identified—just as, here, it was the previously unidentified rapist.”

Collect at Conviction

The dissent contends that the appropriate DNA collection point is at the time of conviction and not at the time of arrest, before an individual is legally adjudicated.

“All parties concede that it would have been entirely permissible, as far as the Fourth Amendment is con­cerned…to take a sample of King’s DNA as a consequence of his conviction for second-degree assault. So the ironic result of the court’s error is this: The only arrestees to whom the outcome here will ever make a difference are those who have been acquitted of the crime of arrest—so that their DNA could not have been taken upon conviction. In other words, this act manages to burden uniquely the sole group for whom the Fourth Amendment’s protections ought to be most jealously guarded: people who are innocent of the state’s accusations.”

Fingerprint Collections Differ From DNA Collections

Scalia dismisses the majority’s analogies to other information collected from arrestees, such as photographs, citing photographs do “not involve a physical intrusion on the person,” and fingerprints. “Fingerprints of arrestees are taken primarily to identify them (though that process sometimes solves crimes); the DNA of arrestees is taken to solve crimes (and nothing else)…Today, it can fairly be said that fingerprints really are used to identify people—so well, in fact, that there would be no need for the expense of a separate, wholly redundant DNA confirmation of the same information. What DNA adds—what makes it a valuable weapon in the law­ enforcement arsenal—is the ability to solve unsolved crimes, by matching old crime-scene evidence against the profiles of people whose identities are already known…Solving unsolved crimes is a noble objective, but it occupies a lower place in the American pantheon of noble objectives than the pro­tection of our people from suspicionless law-enforcement searches. The Fourth Amendment must prevail.”

Are Traffic Offenders Next to Provide DNA?

Scalia makes an ominous prediction about the potential for expansive DNA collections as a consequence of the court’s decision.

“If one believes that DNA will ‘identify’ someone arrested for assault, he must believe that it will ‘identify’ someone arrested for a traffic offense. When there comes before us the taking of DNA from an arrestee for a traffic violation, the court will predictably (and quite rightly) say, ‘We can find no significant difference between this case and King.’ Make no mistake about it: As an entirely predictable consequence of today’s decision, your DNA can be taken and entered into a national DNA database if you are ever arrested, rightly or wrongly, and for whatever reason.”

Foreshadowing Concerns about Collecting Phone Metadata?

The dissent’s final salvo questions whether the ends—solving crimes—justifies collecting DNA from many groups, not just arrestees, is eerily evocative of the intense public debate following disclosure of the NSA’s collection of phone metadata, revealed just two days after this decision was published.

 “Today’s judgment will, to be sure, have the beneficial effect of solving more crimes; then again, so would the taking of DNA samples from anyone who flies on an air­plane (surely the Transportation Security Administration needs to know the ‘identity’ of the flying public), applies for a driver’s license or attends a public school. Perhaps the construction of such a genetic panopticon is wise. But I doubt that the proud men who wrote the charter of our liberties would have been so eager to open their mouths for royal inspection.”

Mark J. Becker, an attorney and CIPP/US/G, is a former privacy consultant to government and private sector clients and served as a senior attorney and privacy officer for a publicly traded market research company. Mr. Becker is a published author of book chapters and articles on privacy and telecommunications law and currently serves as a senior policy advisor with the U.S. Department of Homeland Security (DHS). This article reflects his own interpretation, views and opinions and not those of DHS.

