Reasonable Suspicion / Probable Cause for DUI Stop

Constitutional issues in DUI cases that have been addressed by the U.S. Supreme Court are briefly summarized. State statutes and case law must also be considered when reviewing these types of cases. The main issues addressed are the traffic stop which requires reasonable suspicion or probable cause, the brief detention which also requires a reasonable suspicion, and finally the arrest which requires probable cause.

Reasonable Suspicion (“specific and articulable facts” to stop)
Terry v. Ohio, 392 U.S. 1 (1968)
“. . .the police officer must be able to point to specific and articulable facts which, taken together with rational inferences from those facts, reasonably warrant that intrusion.”
Florida v. Royer, 460 U.S. 491 (1983)
. . . law enforcement officers do not violate the Fourth Amendment by merely approaching an individual on the street or in another public place, by asking him if he is willing to answer some questions, by putting questions to him if the person is willing to listen, or by offering in evidence in a criminal prosecution his voluntary answers to such questions.

Third Party Tip
Florida v. J.L., 529 U.S. 266(2000)
Finally, the requirement that an anonymous tip bear standard indicia of reliability in order to justify a stop in no way diminishes a police officer's prerogative, in accord with Terry, to conduct a protective search of a person who has already been legitimately stopped.

Probable Cause to Make Traffic Stop
Whren v United States , 517 U.S. 806 (1996)
Do not have “to determine whether a ‘reasonable officer’ would have been moved to act upon the traffic violation. . .
Here the District Court found 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.

Brief Investigatory Detention (Reasonable suspicion for brief detention; traffic stops are an investigative detention)
Florida v. Royer, 460 U.S. 491 (1983)
This much, however, is clear: an investigative detention must be temporary and last no longer than is necessary to effectuate the purpose of the stop. Similarly, the investigative methods employed should be the least intrusive means reasonably available to verify or dispel the officer's suspicion in a short period of time.
Brown v. Texas, 443 U.S. 47 (1979)
The application of Tex. Penal Code Ann., Tit. 8, § 38.02 (1974), to detain appellant and require him to identify himself violated the Fourth Amendment because the officers lacked any reasonable suspicion to believe appellant was engaged or had engaged in criminal conduct. Accordingly, appellant may not be punished for refusing to identify himself, and the conviction is Reversed.
Hiibel v. Sixth Judicial District Court of Nevada, Humboldt County et al., 124 S. Ct 2451 (2004)
A state law requiring a suspect to disclose his name in the course of a valid Terry stop is consistent with Fourth Amendment prohibitions against unreasonable searches and seizures.
Arizona v. Johnson, 555 U.S. ___, 129 S. Ct 781 (2009)
For the duration of a traffic stop, we recently confirmed, a police officer effectively seizes "everyone in the vehicle," the driver and all passengers. Brendlin v. California, 551 U.S. 249, 255, 127 S.Ct. 2400, 168 L.Ed.2d 132 (2007). Accordingly, we hold that, in a traffic-stop setting, the first Terry condition—a lawful investigatory stop—is met whenever it is lawful for police to detain an automobile and its occupants pending inquiry into a vehicular violation. The police need not have, in addition, cause to believe any occupant of the vehicle is involved in criminal activity. To justify a patdown of the driver or a passenger during a traffic stop, however, just as in the case of a pedestrian reasonably suspected of criminal activity, the police must harbor reasonable suspicion that the person subjected to the frisk is armed and dangerous.

Voluntary Conversation
People v. Rockey, 752 N.E.2d 576, (2001)
Dealt with the issue of when a voluntary conversation between a citizen and an officer becomes a seizure. The court concluded that “in reviewing the lawfulness of a search and seizure, when the trial court’s ruling involves factual determinations and credibility assessments, the decision will be reversed on appeal only if it is manifestly erroneous or against the manifest weight of the evidence-that is, only where an opposite conclusion is clearly evident for the record.”
Kunz, Michael B. “One Free Swerve? Requiring Police to Corroborate Anonymous Tips in Order to Establish Reasonable Suspicion for Warrantless Seizure of Alleged Drunk Drivers.” American University Washington College of Law, Distinguished Student Research Papers, (2010). This paper argues that in order to use third-party information as the basis for a stop or search, police must first ascertain the informant’s reliability by either discovering the tipster’s identity or verifying sufficient predictive information related to the alleged crime.
Morrissey, Colby J. “Anonymous Tips Reporting Drunk Driving: Rejecting a Fourth Amendment Exception for Investigatory Traffic Stops,” New England Law Review 9, 38 (2010). This article looks at the current disagreement among federal and state courts regarding traffic stops based on an anonymous tip reporting drunk driving. It argues for a balance of the two approaches.
Kuligowski, Monte. “Rethinking DUI Law in Virginia,” University of Richmond Law Review 42, (2007). Using Virginia as the primary focus, this article looks at the failure to always require the requisite criminal intent for conviction when prosecuting DUIs.
McCrea, Jacob C. “Reasonable Suspicion, Probable Cause, or Something in Between: What is the standard for valid vehicle stop in drunk driving cases, and will courts adhere to that standard?” Duquesne Law Review 42, (2004). This article focuses on the inconsistency of the Pennsylvania lower courts in applying the proper standards to determining probable cause for DUI stops.
Sonntag, Geoffrey C. “Probable Cause, Reasonable Suspicion, or Mere Speculation?: Holding Police to a Higher Standard in Destruction of Evidence Exigency Cases,” Washburn Law Journal 15, 4 (June 2003). This article examines the argument between the fourth amendment, requiring policy to obtain a search warrant, and the circumstances in which police may make a warrantless search of a residence to prevent the loss of evidence. 
Spellmeier, Luke R. “Bypassing the Fourth Amendment: The Missouri Supreme Court’s Use of “Ruse” Reasonable Suspicion to Justify De Fact Drug Interdiction Checkpoints,” Washburn Law Review 17, 31 (2003). Using State v. Mack, as its primary critic, this article artgues that the Missouri Supreme Court failed to recognize applicable United States Supreme Court precedent by wrongly upholding a de facto drug interdiction checkpoint, thus allowing the reasonable suspicion standard to be satisfied by nothing more than a simple “hunch.”