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Attenuation Doctrine


This past month the U.S. Supreme Court handed down two decisions officers should review. The first is Utah v. Strieff.


In Utah v. Streiff, officers received anonymous tips about narcotics activity at a residence. Officers conducted surveillance of the residence and saw persons arriving and leaving the house in short durations which they knew to be evidence of drug dealing.

After a week or so of surveillance officers made a pedestrian stop on an individual who left the house. The officers had not seen the suspect enter the house. As part of the stop officers asked for his identification which the suspect provided. The officer ran the defendant and learned defendant had a traffic warrant. Defendant was arrested on the warrant and was searched incident to arrest. Methamphetamine and drug paraphernalia were found on the defendant.


The defendant moved to suppress. The trial court denied the motion finding the evidence should not be suppressed because the arrest warrant attenuated the connection between the illegal stop and the discovery of contraband. The Utah Supreme Court reversed. The USSC decided the case to address how attenuation applies where there is an illegal detention that leads to the discovery of a valid warrant.


The court reiterated that to enforce the Fourth Amendment courts at times must exclude evidence obtained by unconstitutional conduct. The court also reiterated that the significant costs of suppression should only apply where deterrence outweighs the substantial social cost.

The court recognized three exceptions, among others, to the exclusionary rule.

1. The independent source doctrine allows evidence obtained in an unlawful search to be admissible if officers obtained it from an independent source.
2. Inevitable discovery allows for the admission of evidence that would have been discovered without the unconstitutional acts.
3. The attenuation doctrine allows evidence to be admitted when the connection between unconstitutional police practice is remote or has been interrupted by an intervening circumstance so that the violation is not served by suppression.

The test is the link between the unlawful act by the officer and the discovery of evidence, often with no defense action.

The court looked at three factors:

1. The amount of time between the unconstitutional conduct and the discovery of evidence. Generally the closer in time the more likely the evidence will likely be suppressed.
2. The presence of intervening circumstances. Here, the intervening circumstance was the discovery of the valid arrest warrant.
3. The court evaluates the purpose and flagrancy of the official misconduct. The more flagrant the misconduct the more it needs to be deterred. Negligence, errors in judgment etc., are not enough. Systemic or recurrent police misconduct is required.

The Court found that the second two factors weighed in the government’s favor and found that once the detective discovered the warrant he had an obligation to arrest the defendant and search him subject to arrest. The illegal stop was considered an isolated incident and the Court found the officers made two “good faith mistakes.” The officers stopped the suspect without knowing how long he had been in the house and then demanded he speak with them rather than asking the defendant to speak. Thus the Court declined to suppress the evidence.

Birchfield v. North Dakota 2016 DJDAR 6086

The second case is, Birchfield v. North Dakota 2016 DJDAR 6086, which held in essence, that the Fourth Amendment permits warrantless breath tests, but not blood tests. The decision is based on the minimal intrusion of a breath test and because the government does not retain evidence after a breath test. A warrant is still required to take blood when there is a refusal.


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