The collective knowledge doctrine is a legal theory used in the state to give law enforcement officers expanded opportunities to legally perform a search on a criminal suspect without a warrant. Generally, the doctrine has allowed police and prosecutors to successfully argue that any single police officer involved in an investigation or pursuit is entitled to perform a warrantless search or arrest if any other officer involved in the investigation, or a combination of them, had sufficient knowledge to justify the apparent constitutional violation. This doctrine has been applied in the state even under circumstances where the officer performing the warrantless intrusion had not communicated with any other officers about what they knew.
The Massachusetts Supreme Court recently addressed an appeal challenging the application of this doctrine in light of state constitutional protections afforded by Article 14 of the Massachusetts Constitution. The defendant from the recently decided case was searched and arrested on suspicion of armed robbery after reports came in of a suspect that allegedly matched the description of the suspect, who police had encountered on the street. The search of the defendant revealed cash and a gun, and the victim of the crime later identified the defendant as the perpetrator of the robbery.
At the defendant’s trial, his counsel moved to suppress the evidence found in the search, arguing that the officer who performed the search did not have reasonable suspicion that the defendant was actually the suspect. The trial court denied the defendant’s motion, ruling that under the collective knowledge doctrine, the arresting officer could be imputed with all of the cumulative knowledge of any law enforcement personnel involved in the investigation, and with that knowledge, reasonable suspicion could be demonstrated. The defendant was ultimately convicted of the crimes he was charged with, and sentenced to a prison term.