Rodriguez v. United States, 135 S. Ct. 1609

Background

At 12:06 a.m. Officer Struble stopped a Mercury Mountaineer for briefly driving on the shoulder; two occupants were in the vehicle (driver Rodriguez and passenger Pollman).
Struble ran license/registration/insurance checks, questioned both occupants, called for backup, and issued Rodriguez a written warning by about 12:27–12:28 a.m.
After issuing the warning (and before Rodriguez was told he was free to leave), Struble ordered Rodriguez out, waited for a deputy, then walked his drug‑detection dog twice around the vehicle; the dog alerted and police found methamphetamine.
Lower courts (magistrate, district court, Eighth Circuit) treated the 7–8 minute delay for the dog sniff as a de minimis extension and upheld the seizure; Rodriguez was convicted after a conditional guilty plea.
The Supreme Court granted certiorari to resolve a split on whether police may extend an otherwise‑completed traffic stop, absent reasonable suspicion, to conduct a dog sniff.
The Court held that a seizure justified only by a traffic violation becomes unlawful if it is prolonged beyond the time reasonably required to complete the mission of the stop; it vacated the Eighth Circuit judgment and remanded. The Court left open whether reasonable suspicion supported the post‑completion detention.

Issues

Issue	Plaintiff's Argument (Rodriguez)	Defendant's Argument (Government/Officer)	Held
May police, without reasonable suspicion, extend an otherwise‑completed traffic stop to conduct a dog sniff?	The dog sniff occurred after the traffic stop's mission was complete and thus was an unlawful prolongation absent reasonable suspicion.	A brief, objectively reasonable post‑completion delay (de minimis) to run a dog sniff is permissible, especially if the officer diligently completed traffic tasks.	The Court: No. Extending a stop beyond the time reasonably required to complete the stop's mission violates the Fourth Amendment; a dog sniff that prolongs the stop is unlawful absent reasonable suspicion.
Is a dog sniff an ordinary inquiry incident to a traffic stop (part of the stop's mission)?	Dog sniffs detect evidence of general criminal wrongdoing and are not part of the traffic‑safety mission; they cannot be used to justify post‑completion detention absent suspicion.	A dog sniff does not change the character of a lawful stop if it does not extend the duration; routine checks and certain unrelated inquiries are permitted if they do not prolong the stop.	The Court: A dog sniff is not part of the traffic‑safety mission and cannot justify prolonging a stop absent reasonable suspicion; unrelated checks are allowed only so long as they do not measurably extend the stop.
Was the specific 7–8 minute delay here justified by reasonable suspicion?	Rodriguez: No reasonable suspicion supported the continued detention after the warning.	Government: The officer had reasonable suspicion based on nervous behavior, masking odors, implausible travel story, etc.	The Court: Did not decide. The Court remanded for the Eighth Circuit to consider whether reasonable suspicion existed.

Key Cases Cited

Illinois v. Caballes, 543 U.S. 405 (2005) (dog sniff during a lawful traffic stop that does not prolong the stop does not violate the Fourth Amendment)
Arizona v. Johnson, 555 U.S. 323 (2009) (questions unrelated to the traffic stop are permissible so long as they do not prolong the stop)
Knowles v. Iowa, 525 U.S. 113 (1998) (traffic stop is more analogous to a Terry stop than an arrest; duration tied to the stop's mission)
Terry v. Ohio, 392 U.S. 1 (1968) (permitting limited investigative detentions on reasonable suspicion)
Pennsylvania v. Mimms, 434 U.S. 106 (1977) (minor additional intrusions justified by officer safety)
Delaware v. Prouse, 440 U.S. 648 (1979) (routine checks incident to traffic enforcement include license and registration inspections)
Florida v. Jardines, 569 U.S. 1 (2013) (dog sniff is aimed at detecting evidence of ordinary criminal wrongdoing)
United States v. Sharpe, 470 U.S. 675 (1985) (duration of a stop judged by whether police diligently pursued investigation)
Whren v. United States, 517 U.S. 806 (1996) (objective reasonableness governs traffic stops regardless of officer's subjective intent)