The Massachusetts Office of Alcohol Testing admitted to withholding documents in a court case related to breathalyzer equipment failing calibration tests -- a move that could potentially imperil the results of thousands of drunk driving cases.

"They turned over all the times the machine was successfully calibrated. They didn't turn over the 413 times it failed," said Joseph Bernard, a Springfield-based lawyer who was one of the lead defense attorneys in the case challenging the validity of the breath tests. "That was not fair to any of us -- not to the prosecutors and certainly not to the citizens."

In a letter to Middlesex County District Attorney Marian Ryan, Secretary of Public Safety Daniel Bennett said he has concluded that a number of documents that should have been provided to prosecutors by the Office of Alcohol and Testing were not produced. He has ordered an investigation.

State prosecutors have temporarily halted the use of breathalyzer evidence in trials.

A judge ruled in February that any breathalyzer test calibrated between June 2012 and September 2014 cannot be used by the state in any criminal prosecution unless the prosecution proves that that particular test was properly calibrated. The ruling came after a group of drunken driving defendants challenged the reliability of the Alcotest 9150 equipment. A judge found that the test is reliable, but questioned the lax standards used by the Massachusetts Office of Alcohol Testing to calibrate the tests.

According to Bernard, 58,000 breath tests done in Massachusetts could be impacted.

During the discovery phase of the trial, the Office of Alcohol Testing gave the attorneys 1,972 worksheets documenting calibrations of the alcohol test. Only 11 of those worksheets showed failed calibration attempts. However, defense attorneys later discovered that 431 worksheets were removed before the documents were provided -- and 419 of them showed failed calibration attempts.

Bernard said if those worksheets had been released, drunken driving defendants could have used them to prove the test is not reliable.

"They had a right to know that the machine wasn't working properly and let a judge or jury decide how important it was," Bernard said.

Bernard and attorney Thomas Workman filed a motion requiring the state to produce the documents. They asked a judge to dismiss all drunk driving cases affected by the tests and award attorneys' fees and costs.

In response, Bennett wrote in his letter to Ryan that he has ordered attorneys from his office to conduct an internal investigation into the Office of Alcohol Testing -- to review documents, protocols and emails, and interview personnel in order to find out what happened and suggest any necessary changes.

Bennett said he will also hire a retired judge to oversee determinations of the department's future discovery obligations related to the Office of Alcohol Testing and the State Police Crime Lab.

The crime lab is currently embroiled in court cases related to one chemist who falsified drug testing results and another chemist who stole drug evidence.

"I am committed to ensuring that our process is transparent and that any shortcomings that are identified are properly remedied," Bennett wrote.

Meghan Kelly, a spokesman for Ryan's office, said as soon as prosecutors get additional material from the Office of Alcohol testing, they will provide those documents to the defense. Prosecutors have asked for an expedited date to meet with a judge to consider next steps.

Kelly said Massachusetts District Attorneys will no longer use breathalyzer evidence in trials or plea negotiations "until we receive information from OAT and have a full understanding of the nature and scope of the issue."

Bernard said he commends Bennett for acknowledging the error, although he is asking for a more significant remedy.

"It gives people confidence to say, listen, we have an agency who made a colossal blunder and we're going to remedy that," Bernard said.

A hearing is scheduled for next Friday in Salem District Court.

This story was updated with additional reporting.

Sec. Bennett Letter to DAs Re OAT - 8-31-17 by Anonymous PvdTuKps on Scribd