State v. Mitcham

In 2015, during a DUI arrest, the defendant in this case consented to the government collecting a sample of his blood solely to test it for blood-alcohol content, and was advised that the sample would be destroyed after 90 days. Instead, law enforcement held on to this sample for three years, at which point it used it for a completely different purpose—to extract and analyze the appellee’s DNA, without a warrant or consent—while investigating another crime.

Given the revealing nature of DNA, collecting and analyzing it constitutes a seizure and a search under the Fourth Amendment. Our DNA contains some of our most private and sensitive information—ancestry, family relationships, propensities for serious medical conditions, and more. When combined with other public data, it can also expose previously unknown family histories of adoptions, misattributed paternity, or early mortality. The government must therefore obtain a warrant to search or seize DNA. A person’s limited consent to a search of biological material for a specific purpose—in this case, a blood alcohol test for a DUI arrest—does not overcome that requirement.

The ACLU and the ACLU of Arizona filed an amici curiae brief urging the Court to affirm the lower court’s decision that this search violated the appellee’s Fourth Amendment rights. The brief underscores how extraction and analysis of the highly personal and sensitive information stored in a person’s DNA, without a warrant and beyond the scope of consent, is unlawful. The brief also emphasizes that accepting the State’s arguments in this case—that it can obtain DNA profiles from any biological sample in its lawful possession without any court oversight or approval—would mean that law enforcement could genetically test everything from blood samples taken from newborn babies to identify life-threatening diseases to the organ’s individuals have donated for transplant. Given the sensitive information stored in an individual’s DNA, and the rapidly evolving technology in this area, we argue that adopting the State’s arguments would violate reasonable expectations of privacy and have far-reaching and troubling consequences.