In Birchfield v. North Dakota, the Supreme Court recognized a distinction between substitute methods for testing blood alcohol contents: pursuant to a DUI arrest, breathalyzer tests may be performed without a warrant, whereas blood draws (even if pursued for the exact same reason) may not. My focus here, in this Note, is on roadside saliva swab testing, a method used by police to determine whether a driver is driving under the influence of cannabis. Ultimately, this Note argues for warranted saliva swab testing, resting on a straightforward analogy: A is more like B than it is like C—or, in this particular case, saliva swabs are more like blood draws than breathalyzer tests. And, for this reason, as with blood draws, officers should be required to procure a warrant prior to conducting a roadside saliva swab test.
Ormrod, Demery J., "Roadside Saliva Swab Testing: A Solution to Drugged Driving or a Violation of the Fourth Amendment Right to Privacy?" (2021). Connecticut Law Review. 500.