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Drug Recognition Experts

For a comprehensive look at DRE case law, please visit our DRE page.

Constitutional Considerations

Fourth, Fifth, and Sixth Amendment cases both historic and recent to illustrate the constitutional considerations inherent in impaired driving cases. Much thanks to Greg Hurley and the National Center for State Courts for their contributions to this section.


Probable Cause to Make Traffic Stop 


Whren v. United States, 517 U.S. 806 (1996).
In this case, the Supreme Court ruled that any traffic violation committed by a driver is a legitimate legal basis to make a traffic stop, even if the stop was pretextual. The Court stated that "the officers had probable cause to believe that petitioners had violated the traffic code. That rendered the stop reasonable under the Fourth Amendment, the evidence thereby discovered admissible, and the upholding of the convictions by the Court of Appeals for the District of Columbia Circuit correct."



The Court differs on the constitutionality of  sobriety (Michigan Dept. of State Police v. Sitz) and narcotics (City of Indianapolis v. Edmond) checkpoints.


Third Party/Anonymous Tips


Navarette v. California, 572 U.S. ___, 134 S. Ct. 1683 (2014).
In this case, police received a tip that a truck had recently run the caller off the road, and the caller gave a specific description of the make, model, color and license plate of the vehicle. Police found the truck and followed it for about five minutes, but did not observe any suspicious behavior. Nonetheless, they conducted a traffic stop and found thirty pounds of marijuana in the truck. At trial, the occupants of the truck argued that the tip was unreliable, but on appeal, the Supreme Court found the tip to be reliable and held that law enforcement does not need to personally observe criminal activity when acting upon information provided by an anonymous 911 call. Justice Scalia wrote a strong dissenting opinion in the case in which he argued that the tip was unreliable and that the Court’s opinion “serve[d] up a freedom-destroying cocktail consisting of two parts patent falsity.”


Brief Investigatory Detention (Reasonable suspicion for brief detention; traffic stops are an investigative detention)


Arizona v. Johnson, 555 U.S. 323 (2009).
In this case, the Court held that police may conduct a pat down search of a passenger in a vehicle that has been stopped for a traffic violation, so long as the police have reasonable suspicion that the passenger is armed and/or dangerous.


Brendlin v. California, 551 U.S. 249 (2007).
In this case, the Court held that all occupants of a car are "seized" for Fourth Amendment purposes during a traffic stop, not just the driver.

Pennsylvania v. Mimms, 434 U.S. 106 (1977).
In this case, the Supreme Court held that a police officer may order a driver out of a car and conduct a pat-down of that person without violating the protections of the Fourth Amendment. In Maryland v. Wilson, 519 U.S. 408 (1997), the Court extended that rule to passengers in a vehicle, as well.


Probable Cause



Arizona v. Gant, 556 U.S. 332 (2009).
In this case, the Supreme Court held that police may search a vehicle incident to a recent occupant's arrest only if the arrestee is within reaching distance of the passenger compartment at the time of the search (in an effort to protect law enforcement) or it is reasonable to believe the vehicle contains evidence of the offense of arrest (in order to preserve evidence relating to the arrestee's crime).


Maryland v. King, 569 U.S. ___, 133 S. Ct. 1958 (2013).
In this case, the Court held that "when officers make an arrest supported by probable cause to hold for a serious offense and 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."

Missouri v. McNeely, 569 U.S. ___, 133 S. Ct. 1552 (2013).
In this case, the Supreme Court rejected the theory stemming from Schmerber v. California that the natural dissipation of alcohol in the bloodstream was a per se "exigent circumstance" that permitted law enforcement to "search" someone in custody and take a blood sample without a warrant. Instead, the Court affirmed that exigency in impaired driving cases must be determined on a case-by-case basis.

Birchfield v. North Dakota, 579 U.S. ___, 136 S. Ct. 2160 (2016).
In this case, the Court held that warrantless breath tests are permitted under the search incident to arrest doctrine but not warrantless blood tests (the latter having been established by McNeely), finding that blood tests are significantly more intrusive, implicate significantly more privacy concerns, and that their objective can be reached by other less intrusive means (namely breath tests).

Utah v. Strieff, 579 U.S. ___, 136 S. Ct. 2056 (2016).
In this case, the Supreme Court ruled that evidence found by police officers after illegal stops may be used in court if the officers conducted their searches after learning that the defendants had outstanding arrest warrants. In this case, police did not have reasonable suspicion to stop the defendant, but they stopped him and found an outstanding warrant for a traffic violation. The officers searched the defendant and found narcotics and drug paraphernalia. Although the stop was illegal, the Court said that the exclusionary rule did not apply because "the existence of a valid arrest warrant attenuated the connection between the unlawful stop and the discovery of the contraband."


Statements to Law Enforcement

Admissibility of incriminating statements, admissions, or confessions must be examined in terms of whether or not the encounter is an ordinary traffic stop or a custodial interrogation, which requires the procedural safeguards set forth in Miranda. Issues related to admission of laboratory results must be decided based on the confrontation clause analysis provided in Crawford, Bullcoming, and Melendez-Diaz.

Miranda Rights and Traffic Stops


Pennsylvania v. Bruder , 488 U.S. 9, 109 S. Ct. 205 (1988).
In this case, the Supreme Court re-emphasized that ordinary traffic stops do not involve custody for the purposes of Miranda, and therefore, police do not need to inform those stopped for traffic violations of their Miranda rights unless taken into custody.



Chain-of-Custody and Other Evidentiary Issues


Bullcoming v. New Mexico, 564 U.S. 647 (2011).
In this case, the Supreme Court held that the accused’s right is to be confronted with the analyst who made the certification or performed a test of the evidence and transcribed its results from the lab equipment used to conduct the test, unless that analyst is unavailable at trial and the accused had an opportunity to cross-examine that particular scientist before the trial.

Williams v. Illinois, 566 U.S. ___, (2012).
In this case, the Supreme Court ruled that an expert may base an opinion on the results of tests and experiments conducted by others, even when said expert has no firsthand knowledge of the testing procedure utilized, without violating the Confrontation Clause, distinguishing the Court's holdings in Crawford and Bullcoming.

Melendez-Diaz v. Massachusetts, 557 U.S. 305 (2009).
In this case, the Supreme Court held that it was a violation of the Confrontation Clause of the Sixth Amendment for a prosecutor to submit a chemical drug test report without the testimony of the person who performed the test. However, in its decision, the Court also stated that “[w]e do not hold, and it is not the case, that anyone whose testimony may be relevant in establishing the chain of custody, authenticity of the sample, or accuracy of the testing device, must appear in person as part of the prosecution's case. While... it is the obligation of the prosecution to establish the chain of custody, this does not mean that everyone who laid hands on the evidence must be called.”


State Case on Language Barriers and DUI

Rodriquez v. State No. S02A0412 (June 24, 2002). 
In this case, the Georgia Supreme Court held that a non-English-speaking defendant convicted of DUI was not denied equal protection or due process under the United States Constitution or the Georgia Constitution when the results of his blood-alcohol tests were admitted to trial, even though the implied consent warning required under Georgia's implied consent statute was not read or interpreted in a language that the defendant could understand.

State Case Law and Agency Decisions

Coming soon!


Coming soon!

The Judicial Resource Center on Drug-Impaired Driving thanks Greg Hurley and the National Center for State Courts or their contributions to this page.

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