The discovery of a valid arrest warrant during an unconstitutional investigatory stop can attenuate the taint of the stop, the U.S. Supreme Court held June 20. 

In Utah v. Strieff, the Court ruled that even though an initial stop was illegal, evidence found during the stop need not be suppressed because the officer discovered a warrant for the defendant during the stop, and could arrest him on the warrant and search him incident to the arrest. 

The Court, however, placed some limitations on its ruling, which might help the defense in future cases.


A police officer stopped Edward Strieff, after he left a suspected drug house.  The officer asked for identification, which Strieff produced.  The officer then ran a warrant check on Strieff, which turned up an outstanding warrant for a traffic violation.  The officer arrested Strieff, searched him incident to the arrest, and discovered drugs.

Strieff moved to suppress the drugs at his trial for unlawful possession. 

The State conceded that police lacked reasonable suspicion for the stop, but argued that discovery of the arrest warrant attenuated its taint.


The Supreme Court agreed, in a 5-3 decision. 

“Evidence is admissible when the connection between the unconstitutional police conduct and the evidence is remote or has been interrupted by some intervening circumstance, so that ‘the interest protected by the constitutional guarantee that has been violated would not be served by suppression,’” the Court said.

Three factors must be examined to decide when to apply the attenuation exception to the exclusionary rule, the Court said.  The first is the time elapsed between the unconstitutional conduct and the search.  The shorter the time, the less likely that attenuation applies.  This factor favored suppression in Strieff’s case, the Court said.  But the other two factors did not.
The second factor is the presence of intervening circumstances.  The arrest warrant predated the stop, and was entirely unconnected to it, the Court said.  Once the warrant was discovered, the officer had a duty to arrest Strieff, and could search him incident to arrest.

The third — and most “significant” – factor is the purpose and flagrancy of the official misconduct.  “The exclusionary rule exists to deter police misconduct,” the Court said.  Exclusion should occur “only when the police misconduct is most in need of deterrence – that is, when it is purposeful or flagrant.”

The officer lacked a sufficient basis to believe that Strieff may have been involved in a drug transaction, and should have asked Strieff whether he would speak with him, instead of demanding that Strieff do so, the Court said.  “But these errors in judgment hardly rise to a purposeful or flagrant violation of Strieff’s Fourth Amendment rights.”

“For the violation to be flagrant, more severe police misconduct is required than the mere absence of proper cause for the seizure,” the Court said. 

The Court noted that several factors mitigated the officer’s conduct.  The officer’s conduct after the stop was “lawful,” and “there is no indication that this unlawful stop was part of any systemic or recurrent police misconduct,” the Court said.
“This was not a suspicionless fishing expedition ‘in the hope that something would turn up,’” the Court added.  The officer was seeking to find out information about what was going on inside a house that was “legitimately” suspected of being a drug house, the Court said.

“Were evidence of a dragnet search presented here, the application of the … factors could be different,” the Court concluded.

Dissenting opinions

Justices Sotomayor, Ginsburg and Kagan dissented.

Sotomayor warned that readers of the majority’s opinion should “not be soothed by the opinion’s technical language,” and said the opinion “allows the police to stop you on the street, demand your identification, and check it for outstanding warrants – even if you are doing nothing wrong.”

She noted that there are almost eight million outstanding arrest warrants in the U.S. today. 

Further, although Strieff was white, “it is no secret that people of color are disproportionate victims of this type of scrutiny,” Sotomayor wrote.  “We must not pretend that the countless people who are routinely targeted by police are ‘isolated’” incidents, she said.

Implications for defense counsel

Despite Sotomayor’s pessimistic warning, defense counsel will need to try to use the limitations cited by the majority to distinguish Strieff in future cases.

Counsel should try to show that the mitigating factors identified in Strieff aren’t present.  For example, counsel should seek to show that police engaged in other misconduct besides the stop or after the stop.

Counsel should seek discovery of and present evidence of “systemic or recurrent” police misconduct in making unconstitutional stops.  This may involve the history and stopping practices of particular officers or police departments, and the history and stopping practices in particular places.  Evidence should be developed that race or other improper factors played a role in the stop.

Finally, counsel should seek to distinguish those cases that are “fishing expeditions” without any articulable reason for the stop.  A client who was merely walking down the street may be differently-situated under Strieff than a client seen leaving a drug house.