The Supreme Judicial Court ruled Thursday that in the absence of state-mandated data on the race and ethnicity of drivers pulled over for traffic stops, minority drivers who feel they were targeted for enforcement no longer have to provide detailed statistical analysis of an officer's traffic stops to prove they were pulled over because of their race or ethnicity.

The determination comes in a ruling in which the state's highest court ruled prosecutors cannot use a gun found in the SUV of a Black man pulled over for an expired inspection sticker in Dorchester's Clam Point section on Nov. 28, 2017.

The court concluded his attorney had provided evidence that he might have been pulled over by gang-unit officers because of his race. If the stop was unconstitutional, then so was any evidence that followed it, in this case, the "gun inside an open bag on the rear passenger seat," the officers said they found while conducting an inventory of the car before having it towed away.

According to the court's summary of the case, the officers found themselves behind a Mercedes SUV and, although the driver was not doing anything wrong, one of the officers fed the vehicle's registration number into a criminal-justice database, which showed that while the driver was a man, it was registered to a woman and that the SUV had an expired inspection sticker. They pulled the driver over, learned he had a suspended license and warrants for driving without a license and ordered him out of the car and put him in handcuffs. Then they found the gun.

The evidence his lawyer used came from a statistical analysis of the officers' "field interrogation and observation" reports and traffic citations. Such a statistical analysis was required under a 2009 ruling, in which the state's highest court explicitly outlawed racial profiling in traffic stops.

But the court noted the lawyer's use of statistics was exceptionally rare, because it's so difficult to get access to them in Massachusetts. A law that briefly required cities and towns to compile and post data on traffic stops, which the court cited in its 2009 ruling, long ago expired and the legislature has resisted efforts to renew the requirement, as recently as this year, the court said.

With no action from the legislature but with what it said was a need to protect minority drivers' constitutional rights, the court said today that, going forward, minority motorists can now use other evidence to make the case they were stopped because of their race or ethnicity.

"While a defendant must show more than the fact that he or she was a member of a constitutionally protected class and was stopped for a traffic infraction, the burden must not be so heavy that it makes any remedy illusory. The requirement that a defendant establish a reasonable inference that a traffic stop was motivated by racial bias means simply that the defendant must produce evidence upon which a reasonable person could rely to infer that the officer discriminated on the basis of the defendant's race or membership in another protected class. Conclusive evidence is not needed."

The court explained the particular difficulties of proving profiling in stops for traffic infractions:

"This court has identified the discriminatory enforcement of traffic laws as particularly toxic. "Years of data bear out what many have long known from experience: police stop drivers of color disproportionately more often than Caucasian drivers for insignificant violations (or provide no reason at all)." Buckley, 478 Mass. at 876-877 (Budd, J., concurring). ...

"The discriminatory enforcement of traffic laws is not a minor annoyance to those who are racially profiled. To the contrary, these discriminatory practices cause great harm. ...

"While the constitutional principle at stake in this case is exceedingly clear--police may not target drivers for traffic stops, citations, and further investigation because of their race--the evidentiary difficulties in identifying racially motivated traffic stops are profound. The traffic stop often constitutes the first and only interaction between a police officer and the occupants of a stopped vehicle; the interaction thus generally provides a minimal amount of direct evidence of the officer's motivations for the particular stop. Additionally, the plethora of potential traffic violations is such that most drivers are unable to avoid committing minor traffic violations on a routine basis, thereby affording officers wide discretion in the enforcement of traffic laws. ...

The totality of the circumstances test, described infra, requires only the evidence necessary to support a reasonable inference that the stop was based on race or membership in another constitutionally protected group."

The court laid out a series of circumstances a defense attorney could use to argue a stop was potentially unconstitutional and ask a judge to conduct a hearing in the case, including whether the stop was by an officer who does not normally do traffic enforcement, the officer's actions during the stop, the "safety interests" in making the stop, and whether the stop complied with the officer's department regulations on traffic enforcement. Also:

"A defendant has a right to reasonable discovery of evidence concerning the totality of the circumstances of the traffic stop; such discovery may include the particular officer's recent traffic stops and motor vehicle-based field interrogations and observations (FIOs)."