CA6 elaborates the collective knowledge doctrine

The DEA had reasonable suspicion for stops of this vehicle in a health care fraud case. The state officers involved could rely on the DEA under the fellow officer rule which has it’s limits, but they weren’t exceeded here. United States v. Lyons, 687 F.3d 754, 2012 FED App. 0229P (6th Cir. 2012).*

Despite its flexibility, the collective knowledge doctrine is not without its restrictions. The doctrine’s primary boundary is, of course, the Fourth Amendment itself. As with any traditional investigative stop, a traffic stop based on collective knowledge must be supported by a proper basis and must remain reasonably related in its scope to the situation at hand. See Davis, 430 F.3d at 354. Accordingly, if an investigating officer “lacked sufficient information to satisfy the reasonable suspicion requirement, and the [responding officer’s] subsequent observations did not produce reasonable suspicion,” then the stop violates the Fourth Amendment. Feathers 319 F.3d at 849. Likewise, if a responding officer exceeds the stop’s scope because he was not provided with the facts necessary to stay within its proper bounds, then any evidence improperly obtained therefrom remains subject to the exclusionary rule, just as if the investigating officer committed the error. See, e.g., United States v. Pineda-Buenaventura, 622 F.3d 761, 776 n.5 (7th Cir. 2010) (finding that the exclusionary rule “remain[ed] in play” when supervisors failed to communicate the proper bounds of a search warrant to executing officers). The taint of a stop effected without reasonable suspicion similarly cannot be cured by an after-the-fact relay of information. See Blair, 524 F.3d at 751-52. Applying traditional Fourth Amendment restrictions equally to the collective knowledge doctrine ensures that communications among law enforcement remain an efficient conduit of permissible police activity, rather than a prophylactic against behavior that violates constitutional rights.

The Seventh Circuit has helpfully clarified the application of the collective knowledge doctrine by identifying three separate inquiries: (1) the officer taking the action must act in objective reliance on the information received; (2) the officer providing the information must have facts supporting the level of suspicion required; and (3) the stop must be no more intrusive than would have been permissible for the officer requesting it. United States v. Williams, 627 F.3d 247, 252-53 (7th Cir. 2010) (citing United States v. Nafzger, 974 F.2d 906, 911 (7th Cir. 1992)). We are persuaded by the simplicity of this approach.

Moreover, and from a purely functional standpoint, practical considerations naturally restrict the collective knowledge doctrine, because a responding officer is invariably in a better position when provided with the details helpful and necessary to perform his duties. The relay of sufficient information is critical to a responding officer who needs to, for example, report to the correct location, identify the correct suspect, respond appropriately to exigent circumstances, and protect his safety and the safety of others.

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Moreover, it is immaterial that the troopers were unaware of all of the specific facts that supported the DEA’s reasonable suspicion analysis. The troopers possessed all the information they needed to act—a request by the DEA (subsequently found to be well-supported) that they execute the traffic stop in the expectation that illegal narcotics would be found in the vehicle. …