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CRIMINAL DEFENSE: Appellate Court Keeps The Collective Doctrine Narrow

CRIMINAL DEFENSE: Appellate Court Keeps the Collective Doctrine Narrow

The Appellate Division of the San Francisco Superior Court has just posted its finding in P. v. Chalak, a decision filed on March 11, 2020. JAD20-03 (Cal. Ct. App. 2020). In P. v. Chalak, the Court found that, in order for the “collective knowledge” doctrine to apply, there must be actual communication between the officer with reasonable suspicion and the detaining officer.

The Facts

Officer Leung was dispatched to a local Macy’s, where Amyah S. gave him a description of her ex-boyfriend, who she said had hit her earlier in the day. Notably, she described him as wearing a grey sweatsuit. Leung broadcast her description over the radio. He then got a call from another officer who had detained a suspect wearing a black sweatsuit.

Leung drove with Amyah to the location where the other officer was holding the suspect. Amyah told the officers that the suspect was not her ex-boyfriend. Leung did not believe her and asked her to call her ex-boyfriend’s phone, which she did, twice. The suspect’s phone rang twice, and the officers took him to the police station.


In court, the Appellant, the suspect, moved to suppress evidence against him due to its unconstitutionality. The Superior Court refused his evidence motion and convicted him of domestic battery. On appeal, the Court of Appeal reversed, finding that the government had failed to submit evidence that the detaining officer had reasonable suspicion to detain the Appellant.

Legal Reasoning

The government argued that the detaining officer had reasonable suspicion under the collective knowledge doctrine because Leung was involved in the arrest and had reasonable suspicion. The Court disagreed, citing and comparing this case with precedent to show that the officer with reasonable suspicion must communicate with the detaining officer in order for the collective knowledge doctrine to apply. Even though Leung broadcasted a description of the suspect, the government did not submit any evidence that the detaining officer had heard the broadcast.

Finally, the Court found that the government failed to provide any evidence that the suspect’s arrest was not fruit of the poisonous tree, and therefore a harmless error.

THE TAKEAWAY: Reasonable suspicion or probable cause may only be used to justify a detention where the detaining officer has received communication from another involved officer who has reasonable suspicion or probable cause. Criminal defense attorneys may find the case helpful, attacking a lack of thoroughness on the part of the arresting agency.

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