Maryland v. King

Following is the case brief for Maryland v. King, 569 U.S. 435 (2013)

Case Summary of Maryland v. King:

  • Maryland collects DNA, by swabbing a person’s cheek, from any person arrested for a serious crime.
  • Respondent King was arrested for assault.  His DNA was taken.  As a result, he was implicated in a rape case from years earlier.
  • He was eventually convicted for the rape.  The trial court denied his motion to suppress the DNA evidence.
  • The Maryland Court of Appeals reversed, finding that the DNA swab violated the Constitution.
  • The U.S. Supreme Court reversed the Maryland Court of Appeals.  It held that taking a cheek swab subsequent to a valid arrest for a serious crime is, like fingerprinting and photographing, a legitimate police booking procedure that is reasonable under the Fourth Amendment.

Maryland v. King Case Brief

Statement of the Facts:

Maryland’s law, the Maryland DNA Collection Act, calls for obtaining a DNA sample from any person arrested for a serious crime.  Respondent King was processed in 2009 following his arrest for first- and second-degree assault.  During the processing, a swab of his cheek was performed to obtain the DNA pursuant to the DNA Collection Act.

The DNA swab was matched with an unsolved 2003 rape.  King was then charged, tried, and convicted of the 2003 rape based on the DNA evidence.  King had moved to suppress the DNA evidence before the trial.

Procedural History:

  • The trial court denied King’s suppression motion.
  • The Maryland Court of Appeals reversed the rape conviction, finding that the DNA Collection Act was unconstitutional in relevant part.
  • The U.S. Supreme Court granted certiorari.

Issue and Holding:

Does taking a DNA sample, via cheek swab, from a person arrested for a serious crime run afoul of the Fourth Amendment?  No.


The decision of the Maryland Court of Appeals is reversed.

Rule of Law or Legal Principle Applied:

A person arrested for a serious offense can have a DNA sample taken via cheek swab without violating the Fourth Amendment because it is a legitimate police booking procedure similar to fingerprinting and photographing.


Taking a DNA sample from a swab of the mouth is a “search” under the Fourth Amendment.  As such, the Court must determine whether the search is reasonable.  That is accomplished by balancing the government interest in the DNA information with the intrusion on an individual’s privacy.

The balancing in this case weighs heavily in favor of the government’s interest in the DNA information. The government has a legitimate interest in a safe and accurate way to process and identify persons and possessions taken into custody.  Also, the government has an interest in knowing a person’s criminal history to determine how much of a safety risk he or she poses.  By contrast, the individual’s privacy interest is minimal because the swab is a minimal intrusion.   Further, the DNA Collection Act has other provisions to protect privacy.

Finally, the collection of DNA is similar to taking an arrestee’s fingerprints and photograph.  Therefore, the Maryland Court of Appeals decision is reversed.

Concurring and Dissenting Opinions:

Dissenting Opinion (Scalia): 

The Fourth Amendment forbids conducting a search when there is no basis for believing the person is guilty of a crime.  With any suspicionless search, the Court requires a motive apart from the investigation of crime.  No such motive exists here.  Further, the Court’s rationale that the DNA is for “identification” is not credible.


Maryland v. King is significant because it now places taking a DNA swab alongside fingerprinting as a routine police booking procedure for arrested individuals.  Those who favor the decision believe it will help solve cold cases, as well as future crimes.  Those against feel that the benefits of solving past crimes does not outweigh the privacy interests at stake.

Student Resources:

Read the Full Court Opinion

Listen to the Oral Arguments