The collective knowledge doctrine does not require that the officer requesting a stop actually tell the other officers the reason why. United States v. Rubio-Sepulveda, 2017 U.S. Dist. LEXIS 23866 (D. Colo. Feb. 21, 2017):
Defendant argues that for the collective knowledge doctrine to apply, the officer with reasonable suspicion or probable cause must communicate his reasons to the officer conducting the stop; otherwise the stop is improper. This Court’s reading of the applicable case law, however, suggests a different conclusion—namely that a suspecting officer may instruct another officer to effectuate stop without communicating the basis for the stop, so long as the communicating officer would be justified in making the stop himself. Id. For example, in Chavez, 534 F.3d at 1347-48, the Tenth Circuit upheld the validity of a traffic stop where a federal agent with probable cause requested that a state officer stop a suspect without communicating to the state officer the reasons for the stop or the nature of the federal investigation. The panel noted, citing multiple courts in agreement, “a police officer may rely on the instructions of the DEA (or other law enforcement agencies) in stopping a car, even if that officer himself or herself is not privy to all the facts amounting to probable cause.” Id. at 1347. Numerous cases in other jurisdictions support this application of the vertical collective knowledge doctrine. See United States v. Ramirez, 473 F.3d 1026, 1037 (9th Cir. 2007) (“We are satisfied that the collective knowledge doctrine includes no requirement regarding the content of the communication that one officer must make to another. Where one officer knows facts constituting reasonable suspicion … and he communicates an appropriate order or request, another officer may conduct a warrantless stop … without violating the Fourth Amendment.”); United States v. Williams, 429 F.3d 767, 771-72 (8th Cir. 2005) (“[W]e also hold that the collective knowledge of the DEA team was sufficient to provide reasonable suspicion to stop [the co-defendant’s] vehicle, and such knowledge was imputed to the officer at the scene when he received [another officer’s] radioed request.”); United States v. Burton, 288 F.3d 91, 99 (3d Cir. 2002) (“[T]he arresting officer need not possess an encyclopedic knowledge of the facts supporting probable cause, but can instead rely on an instruction to arrest delivered by other officers possessing probable cause.”); United States v. Ibarra—Sanchez, 199 F.3d 753, 758-59 (5th Cir. 1999); United States v. Celio, 945 F.2d 180, 183 (7th Cir. 1991).