Prosecutors in Massachusetts can’t use breathalyzer tests in drunken driving cases, with some exceptions, until the state can show that the crime lab that oversees its breath-testing program is likely to receive a certain type of accreditation, a judge has ruled.
The ruling, by District Court Judge Robert A. Brennan, is the latest turn in an ongoing class-action lawsuit that is challenging the accuracy of the state’s breath tests.
The tests have been under scrutiny since 2015, when public safety officials reported some were flawed. That prompted at least eight district attorneys to suspend using the results of breath tests as evidence.
According to Wednesday’s ruling, the Office of Alcohol Testing, which is part of the State Police crime laboratory, must demonstrate that its application for accreditation by the ANSI-ASQ National Accreditation Board is “substantially likely to be approved.”
The group accredits calibration and testing labs, forensic test providers, and police crime units, among others, according to its website.
“In order to remedy the prejudice caused by OAT’s misconduct against the consolidated defendants and the resulting damage to the criminal justice system, OAT must first demonstrate that its current methodology will produce scientifically reliable BAC results,” Brennan wrote.
Currently, 22 labs in 12 states have such accreditation, according to the ruling. The accreditation process involves 10 steps, including an onsite assessment, remedial proposals by the lab, and objective proof by the lab of remediation.
Joseph D. Bernard, a Springfield defense attorney who is representing the class of defendants who are challenging the accuracy of breath tests in Massachusetts, hailed the ruling as a significant victory.
“What it does is it protects the citizens, the courts, and the defense attorneys who demand fair and reasonable discovery practices,” Bernard said Wednesday night.
Several district attorneys said they will continue to prosecute OUI cases and are confident the state lab will gain accreditation.
“We will continue to do our best to hold impaired drivers accountable and are confident that the Office of Alcohol Testing will comply fully with Judge Brennan’s ruling,” Essex District Attorney Jonathon Blodgett said in a statement.
David Traub, a spokesman for the Norfolk district attorney, noted in a statement that “the court found that the instruments are scientifically sound and reliable.”
Traub also noted that “as valuable as a breath test can be, they are only one piece of evidence in any OUI case.”
“The evidence obtained through roadside observations, field sobriety tests, observations of driving irregularities and other facts are already sufficient to satisfy an officer that the driver should be placed under arrest,” he added.
Jake Wark, a spokesman for the Suffolk district attorney, said in a statement that “the decision keeps in place prosecutors’ voluntary agreement since 2015 not to admit breath test evidence in most cases.”
The ruling does not cover all drunken driving cases. Exceptions for the exclusion of breath tests at trial under a previous agreement between defense attorneys and prosecutors include motor vehicle homicide by OUI, OUI causing serious bodily injury, and OUI fifth offense or more, according to court documents.
Messages left with other district attorney’s offices were either not returned or were deferred to another agency.
A State Police spokesman said in a Wednesday e-mail that the agency was withholding comment “until we review the decision.”
The next step in the case, Bernard said, would be for the Office of Alcohol Testing to show the judge its accreditation application is likely to succeed.
Travis Andersen of Globe staff contributed to this report. Danny McDonald can be reached at email@example.com. Follow him on Twitter @Danny__McDonald.