DNA identification of arrestees is a reasonable search that can be considered part of a routine booking procedure. When officers make an arrest supported by probable cause to hold for a serious offense and they bring the suspect to the station to be detained in custody, 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.
King was arrested and charged with first and second degree assault for menacing a group of people with a shotgun. As part of a routine booking procedure for serious offenses, pursuant to the Maryland DNA Collection Act, King 's DNA sample was taken by applying a cotton swab or filter paper, known as a buccal swab, to the inside of his cheeks. The DNA was found to match the DNA taken from a rape victim. Defendant was convicted of the rape crime. The Court of Appeals of Maryland struck down portions of the Maryland DNA Collection Act as unconstitutional and set defendant's rape conviction aside.
Did the Maryland DNA Collection Act violate King’s rights under the Fourth Amendment?
The Supreme Court determined that taking and analyzing a cheek swab of defendant’s DNA was, like fingerprinting and photographing, a legitimate police booking procedure that was reasonable under the Fourth Amendment because, inter alia, (1) the legitimate government interest served by the Act was the need for law enforcement officers in a safe and accurate way to process and identify the persons and possessions they must take into custody, (2) DNA identification of arrestees, of the type approved by the Act, was no more than an extension of methods of identification long used in dealing with persons under arrest, and (3) regarding defendant's legitimate expectations of privacy, the intrusion of a cheek swab to obtain a DNA sample was a minimal one. The Supreme Court reversed the judgment of the Court of Appeals of Maryland