Document Type


Publication Date



This article addresses whether the Fourth Amendment is implicated when police surreptitiously collect and analyze a person’s involuntarily shed DNA. Law enforcement officers will often obtain shed or abandoned DNA samples from persons who they suspect have committed crimes, but lack sufficient evidence to arrest or detain such persons. When utilizing abandoned or shed DNA for criminal investigative purposes, there are two state actions which arguably trigger Fourth Amendment protection. First, the collection of the biological material which contains a person’s DNA might be considered a search under the amendment. Courts, however, have uniformly rejected this argument. For example, when police are interested in determining whether a suspect may be connected with an unsolved crime for which they collected a DNA sample from the crime scene, they will covertly obtain the suspect’s DNA from a fast-food wrapper or hair sample taken from a barber-shop floor. To date, judges have concluded that persons have discarded the DNA-laden cells obtained by police in these circumstances, and thus under Fourth Amendment law, retained no privacy interest in the item seized by police. Second, the analysis of the DNA sample might trigger Fourth Amendment safeguards. This second issue – whether the Fourth Amendment is implicated when police surreptitiously analyze a citizen’s involuntarily shed DNA – is the topic of my paper. Most recently, two state high courts, Maryland and Massachusetts, have rejected Fourth Amendment claims that government analysis of DNA samples lawfully obtained from persons constitutes a search under the Fourth Amendment. The Supreme Court denied certiorari in the Maryland case – Raynor v. Maryland, 99 A. 3d. 753 (Md. 2014), cert. denied, 135 S. Ct. 1509 (2015). The result in Raynor conflicts with a ruling of the United States Court of Appeals for the Fourth Circuit, the federal circuit in which Maryland sits. In United States v. Davis, 690 F. 3d 226 (4th Cir. 2012), the Fourth Circuit ruled that the analysis of a suspect’s DNA sample from clothing lawfully obtained by the police was a search. The Fourth Circuit explained that “analysis required to obtain a DNA profile . . . generally qualifies as a search, because an individual retains a legitimate expectation of privacy in the information obtained from the testing.” However, the Court has requested the Commonwealth of Massachusetts to file a reply to the certiorari petition filed in the Massachusetts case – Commonwealth v. Arzola, 26 N.E. 3d 185 (Mass. 2015). In concluding that analysis of a DNA sample does not constitute a search, both the Maryland and Massachusetts high courts relied heavily on the Supreme Court’s 2013 ruling in Maryland v. King, which held that where police have probable cause to arrest for a serious offense, “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.” Specifically, Part I of my article discusses whether analysis of abandoned DNA constitutes a search under the Fourth Amendment. Part II of the article considers a conflict in the Supreme Court’s cases when new technology or science gives law enforcement authorities enhanced capabilities to discover information arguably protected by the Fourth Amendment. In some cases, when deciding whether a search occurred, or the reasonableness of a challenged search, what a particular intrusion actually reveals matters little; what matters is the potential risk to privacy posed by new technology. In other cases, the fact that a particular intrusion has the potential to disclose highly personal data or massive amounts of information is constitutionally irrelevant. The only thing that matters is what was actually revealed by the intrusion. Finally, Part III of the article considers the implications of leaving the analysis of shed DNA unregulated by the Fourth Amendment.