Writing for the court, Justice Dewar said the Commonwealth failed to justify the twenty-four hours that elapsed between Officer Mathew Pieroway's observation of the infraction in Jamaica Plain and the eventual stop the following afternoon.
"Although a police officer may stop a motor vehicle upon observing a civil traffic infraction, such a stop is a seizure that must be conducted in a reasonable manner," Justice Dewar wrote. "A stop for an infraction is not reasonable if, upon consideration of the totality of the circumstances, the stop occurred after an unreasonable delay."
According to the opinion, Pieroway was surveilling Arias from an unmarked vehicle on March 27, 2019, as part of a drug investigation when he saw Arias's SUV pass a line of about seven stopped vehicles on Centre Street, run a stop sign and turn left in front of the line. Pieroway did not attempt the stop himself and did not call for a marked cruiser. The next afternoon, after relocating Arias, Pieroway radioed, "[W]e're looking to stop a vehicle for [a] drug investigation," and other officers stopped the SUV. A patfrisk yielded cocaine.
The court acknowledged that some delay was reasonable on safety grounds, given that Pieroway was in an unmarked vehicle and the maneuver involved passing a line of stopped cars. But the justices found no record explanation for why Pieroway did not summon a marked cruiser on the day of the infraction, as he testified was his regular practice. Asked at the suppression hearing why he did not call for a marked vehicle, Pieroway "gave a one-word reply of '[s]afety,'" the court noted.
Justice Dewar rejected the idea that the infraction could "hang over a suspect indefinitely until a time at which he has engaged in some other suspicious activity that officers believe warrants a pretextual stop," quoting the court's 2022 decision in Commonwealth v. Daveiga. He wrote that "[t]he nature of traffic citations renders them uniquely suited to manipulation and misuse," quoting Commonwealth v. Pappas.
The court declined to set a bright-line rule, adopting instead the totality-of-the-circumstances approach used by the Fifth Circuit in United States v. Zuniga. Relevant factors include "the length of the delay, any justification for the delay, and the nature of the violation," the opinion said.
On the pretext issue, Justice Dewar reiterated that an officer's ulterior motive does not defeat a traffic stop supported by an observed violation, citing Commonwealth v. Buckley. "Nor, however, does the mere existence of the drug investigation reasonably justify the delay in stopping the defendant for the traffic infraction," he wrote.
Arias had been charged with trafficking 200 or more grams of cocaine. After a first trial ended in mistrial, the Commonwealth successfully moved to reduce the indictment to trafficking one hundred to 200 grams, and at his second trial a jury convicted him of the lesser included offense of trafficking eighteen to thirty-six grams. The SJC vacated the judgment, set aside the verdict and remanded the case to Suffolk Superior Court.
Arias was represented by John P. Warren. Assistant District Attorneys Brooke Hartley and Thomas Laverty appeared for the Commonwealth. Amicus briefs were filed by the Committee for Public Counsel Services, the American Civil Liberties Union of Massachusetts and others.