Thousands of Massachusetts defendants convicted of drunken driving from June 2011 to August 2017 could seek new trials without prosecutors using potentially flawed breathalyzer evidence against them, under terms of a proposed agreement that defense lawyers reached with the state’s 11 district attorneys.
Breath tests have been under scrutiny since 2015, when public safety officials issued a report saying some were flawed. That prompted at least eight district attorneys to suspend using the results of breath tests as evidence.
Thomas Workman, a lawyer who consulted with defense attorneys who negotiated the deal, said in a statement that more than 36,500 breath tests during that time period showed readings above the legal limit, making the evidence issue “the largest in [state] history,” eclipsing the Annie Dookhan drug lab debacle, which resulted last year in more than 20,000 convictions being dismissed statewide.
The agreement is subject to judicial approval, and it’s not clear how many drunken driving convictions could be tossed out. The agreement, finalized on Tuesday, would also offer a do-over for people who were placed on probation after their cases were continued without a finding.
Suffolk Assistant District Attorney Vincent J. DeMore, lead prosecutor in the negotiations, cautioned that the 36,500 tests don’t accurately represent the number of drunken driving defendants who will be affected.
That number of tests, he said, includes people who blew into a machine multiple times, as well as people who took the tests for reasons other than an OUI arrest, such as trying to get released from protective custody at a police station’s so-called drunk tank.
Prosecutors can still seek to use breathalyzer evidence at any retrial involving motor vehicle homicide by driving under the influence, operating under the influence causing serious bodily injury, and operating under the influence, fifth or subsequent offense, the agreement says.
Jake Wark, a spokesman for Suffolk District Attorney Daniel F. Conley, said in an e-mail that the proposed pact does not specifically call for any cases to be dropped.
“It would allow convicted or [continued without a finding] defendants to file a motion for a new trial at which the breath test evidence would not be introduced except under certain circumstances,” Wark wrote.
However, Wark noted, if defendants do seek a new trial, prosecutors can still present evidence such as other drivers’ observations, video footage, and field sobriety tests.
Public safety officials released a scathing report in October that said the state Office of Alcohol Testing routinely withheld documents from defense lawyers in a lawsuit they brought to challenge the test results’ reliability.
The documents included evidence that breath-testing devices had failed to properly calibrate during the office’s certification process, the report said. Conley’s office noted the material was also withheld from prosecutors.
The investigation was conducted by the state’s Executive Office of Public Safety and Security. The Office of Alcohol Testing is part of the State Police crime laboratory and oversees the breath-testing program for the state.
Defense attorney Joseph D. Bernard hailed the deal, which he helped to craft, but said “much work still needs to be done. To correct many deficiencies that exist, the OAT must become accredited. Following the egregious behavior from the Office of Alcohol Testing, the Executive Office of Public Safety and Security’s response was a great first step to begin the restoration of public trust.”
The 2015 state report said fewer than 150 tests were flawed because of mistakes officers had made calibrating the machines and not because the tests themselves were malfunctioning. Tuesday’s agreement said “432 worksheets that represented failures of the annual calibration process” were provided to defense lawyers on Aug. 31 of last year.
Felix Browne, a spokesman for the Executive Office of Public Safety and Security, said Thursday that the agency has full confidence in the reliability of breathalyzers.
“The integrity and accuracy of breath test instruments in use across the Commonwealth at this time has never been determined to be an issue in this case and we stand behind these instruments’ ability to accurately determine the breath alcohol level of drivers charged with operating under the influence,” Browne said in a statement. “The Office of Alcohol Testing has been working diligently to improve transparency by increasing the availability and accuracy of documents and data in its possession.”
There is one key sticking point remaining in Tuesday’s agreement: Prosecutors want to cap the time period for cases in which breathalyzer evidence is barred at Aug. 31, 2017. Defense lawyers want breath tests excluded until the alcohol testing office gets accredited. The testing office has agreed to seek accreditation by August 2019, the pact says.
Judge Robert A. Brennan, who will decide on the entire agreement, will pick a final date for excluding breathalyzer evidence if and when he signs off on the deal.Maria Cramer, Aimee Ortiz, Evan Allen, and John R. Ellement of the Globe staff and Globe correspondent Shawn Musgrave contributed. Travis Andersen can be reached at email@example.com.