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HSEC RUNNER-UP: Maryland v. King: DNA Sampling and the Fourth Amendment


In the 2013 case Maryland v. King, the Supreme Court held that taking DNA samples from people arrested for “serious offenses” did not violate the Fourth Amendment. While being booked into jail on charges of assault, a DNA sample was taken from respondent King, as permitted by the Maryland DNA Collection Act. King’s DNA was later found to match DNA taken from the scene of an unsolved 2003 rape case. Based on that evidence, King was charged and convicted of rape. While longstanding case law gives the government the power to take DNA samples from a person after a conviction, this decision dramatically expanded that power. Now, if an ordinary citizen is arrested, their DNA can be taken and stored in a national DNA database forever—regardless of whether they are actually found guilty of any crime.

Both sides agreed that the buccal swab used to collect King’s DNA sample was a search, and that the search was not based on any individualized suspicion. Justice Anthony Kennedy’s majority opinion found that the search was nevertheless “reasonable” under the Fourth Amendment, because it promoted a legitimate government interest: identifying arrestees. In the majority’s view, this interest outweighed the right to privacy of persons under arrest.

However, as Justice Antonin Scalia pointed out in his dissenting opinion, the State of Maryland did not actually use the DNA samples to identify arrestees, undermining the central argument that the Court used to justify the practice. The police arrested King and sampled his DNA on April 10, 2009, but King’s DNA was not matched to the 2003 rape case until August 4, 2009.[1] After four months, clearly the State of Maryland knew who King was. In fact, he had already been arraigned on assault charges in the meantime. Besides the lengthy timeline, the language of the Maryland DNA Collection Act confirms that the purpose of the Act is not to identify arrestees, but to investigate crimes. Numerous public officials proclaimed that the Act was instrumental in fighting crime, and language on identifying arrestees exists nowhere in the statute.[2]

This is not to say that DNA sampling can never be used for the purpose of identifying arrestees. Indeed, such a use would probably pass constitutional muster. However, Justice Scalia rightly points out that “The issue before us is not whether DNA can someday be used for identification; nor even whether it can today be used for identification; but whether it was used for identification here.”[3] As the language and application of the statute demonstrate, the State of Maryland sampled DNA for the purposes of law enforcement investigation, not identification.

Once the actual purpose of Maryland’s practice of sampling arrestees’ DNA has been established, its constitutionality falls into question. In Indianapolis v. Edmond (2000), the Court found unconstitutional the practice of creating suspicionless checkpoints to check for illegal drugs, noting that it had “never approved a checkpoint program whose primary purpose was to detect evidence of ordinary criminal wrongdoing.”[4] While the Court did approve of suspicionless searches for railroad employees (Skinner v. Railway Labor Executives’ Assn., 1989) and high school students (Vernonia School Dist. 47J v. Acton, 1995), these searches were justified by concerns other than investigating criminal activity. Such circumstances do not exist within the facts of King.

And though the majority opinion in this case correctly notes that police may conduct a search incident to arrest, the breadth of this search is limited. Justice Scalia summarizes the decision in Arizona v. Gant (2009): “The objects of a search incident to arrest must be either (1) weapons or evidence that might easily be destroyed, or (2) evidence relevant to the crime of arrest.”[5] Plainly, neither condition applies to King. Consider the following hypothetical: could the police search an arrestee’s home without a warrant in the interest of solving crimes? Clearly not, as the majority opinion acknowledges. Yet, if we ignore the false rationale of “confirming identity”, Maryland’s practice of taking DNA samples from arrestees has the same justification. It is a suspicionless search—and therefore unconstitutional.

The consequences of this decision are insidious and far-reaching. It is quite plausible that police department will adopt the practice of arresting cold-case suspects for unrelated crimes so that they can obtain a DNA sample. Supreme Court precedent, such as the 2001 case Atwater v. City of Lago Vista, allows officers to make arrests for all criminal violations, even misdemeanors that carry no prison time.[6] In fact, the Los Angeles Police Department used such a tactic during an investigation into a serial killer. They arrested men soliciting prostitutes in areas that the murderer was known to frequent, then asked the arrestees for consent to take a DNA sample.[7] Now, officers do not even need to ask for consent.

While the majority opinion in this case limits police departments to taking samples from those arrested for “serious offenses”, this limitation is not logically sound. If the primary need of DNA samples is to identify arrestees, that need is just as great for someone arrested for jaywalking as it is for assault. “When there comes before us the taking of DNA from an arrestee for a traffic violation,” predicts Justice Scalia, “the Court will predictably (and quite rightly) say, ‘We can find no significant difference between this case and King.”[8]

In a final stroke of irony, even if the Maryland law had been held unconstitutional, King’s DNA could had been sampled anyway—he was convicted for second-degree assault. Consequently, the expansion of police authority as a result of this case only applies to one group: arrestees who are subsequently found innocent. This decision should worry every American. If the police want to test your DNA, they may arrest you for an unrelated minor offense, like a traffic violation. And even if you are acquitted by a jury of your peers, the government will have your genetic information forever.

[1] Maryland v. King, 569 U.S. __ (2013), 8.

[2] Ibid, 10.

[3] Idem, 16.

[4] City of Indianapolis v. Edmond, 531 US 32 (2000), 41.

[5] Maryland v. King, 569 U.S. __ (2013), 4.

[6] Atwater v. Lago Vista. 532 U.S. 318. Supreme Court of the United States. 2001.

[7] Joh, Elizabeth E. “Maryland v. King: Policing and Genetic Privacy.” Ohio State Journal of Criminal Law, vol. 11, no. 1, 2013, 284.

[8] Maryland v. King, 569 U.S. __ (2013), 17.


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