Massachusetts prosecutors withheld evidence of corrupt state narcotics testing for months from a defendant facing drug charges, and didn’t release it until after his conviction, according to newly surfaced documents and emails.

The case of Rolando Penate has become a leading example for lawyers calling for further investigation into alleged misconduct by prosecutors who handled documents seized from Sonja Farak, the Amherst crime-lab chemist convicted of stealing and tampering with drug samples.

Penate is seeking a new trial, contending the conviction should be reversed because of prosecutorial misconduct and evidence tainted by Farak. His is one of what lawyers say could be thousands of convictions questioned in the wake of the Farak scandal. The Farak documents indicate she used drugs on the very day she certified samples as heroin in Penate’s case. B

ut when Penate’s lawyer tried to obtain the documents — not certain what was in them — before his client’s 2013 trial, he was rebuffed by state prosecutors who said the papers were “irrelevant” according to emails included in investigative reports unsealed earlier this month. At the time of Penate’s trial, the state Attorney General’s Office contended Farak’s misdeeds dated back only as far as 2012.

Eight years high

To better estimate how many convictions will have to be reviewed because of Farak, the Supreme Judicial Court ordered a report on the history of her illicit behavior. The report concluded she was usually high while working in the lab for more than eight years before her arrest in January 2013 and started stealing samples seven years ago.

A second unsealed report into allegations of wrongdoing by police and prosecutors who handled the Farak evidence, overseen by retired state judges Peter Velis and Thomas Merrigan, drew less attention. Relying on an investigation conducted by state police, the judges concluded there was “no evidence of prosecutorial misconduct or obstruction of justice” in matters related to the Farak case.

Several defense attorneys who called for the Velis-Merrigan investigation say the former judges and their state police investigators got it wrong. They say court records and newly released emails show prosecutors sat on evidence they were familiar with that pointed to Farak’s drug use in 2011, when she worked on Penate’s case.

"I don’t know how the Velis report reached the conclusion it did after reviewing the underlying email documents,” said Randy Gioia, deputy chief counsel at the Committee for Public Counsel Services, the state’s public defender office. Gioia called for evidentiary hearings “so prosecutors can be asked about what they knew, when they knew it, and what they did with their knowledge.”

Luke Ryan, Penate’s trial lawyer, said that the state police officers working on the report “failed to obtain an appropriate understanding of the events that transpired before they were assigned to this investigation."

Prosecutors have an obligation to give the defense exculpatory evidence – including anything that could weaken evidence against defendants. Compromised drug samples often fit the definition.

Failed to resist

The Attorney General’s Office, Velis and Merrigan and the state police declined to answer questions about the handling of the Farak evidence. Velis said he stood by the findings. “Our posture is to not delve into the twists and turns of the investigation or the report and to let it stand on its own,” Merrigan said.

The former judges and the state police officers who helped them conducted a thorough review, said Emalie Gainey, spokeswoman for Attorney General Maura Healey. Gainey added that Healey is “pleased with their conclusion” that prosecutors and the state police acted appropriately. There is no allegation of misconduct against the local prosecutors who presented the case against Penate in Hampden County Superior Court.

The story of the intertwining Farak and Penate evidence began in January 2013, when state police arrested Farak and searched her car. Among the papers they seized were handwritten worksheets Farak completed for drug-abuse therapy. Farak signed a certification of drug samples in Penate’s case on Dec. 22, 2011.

In worksheet notes dated Thursday, Dec. 22, Farak wrote she "tried to resist using @ work, but ended up failing." Although the year she wrote the notes wasn’t listed on the worksheet, in the six years prior to her arrest, 2011 is the only year in which Dec. 22 fell on a Thursday. Farak’s notes also mentioned a New England Patriots game on Saturday, Dec. 24 which corresponded with a game date in 2011.

Emotional worksheets

Here are those forms with the admissions of drug use I was talking about," a state police sergeant wrote to Assistant Attorney General Anne Kaczmarek, who led Farak’s prosecution, in a February 2013 email, to which he attached the worksheets. His email was one of more than 800 released with the Velis-Merrigan report. In a March 2013 memo, Kaczmarek told her supervisors that "Farak's admissions on her 'emotional worksheets' recovered from her car detail her struggle with substance abuse."

Prosecutors maintained that Farak’s rogue behavior spanned just a few months. But Ryan, who represented Penate, suspected it was more extensive. In an August 2013 email, Ryan asked Assistant Attorney General Kris Foster to review evidence taken from Farak. Foster replied that because the investigation against Farak was ongoing, she couldn’t let him see it. The next month, Ryan asked again. Foster answered that the state considered the evidence “irrelevant to any case other than Farak’s.”

Ryan then filed a motion with Hampden Superior Court Judge Jeffrey Kinder to see the evidence for himself. Foster protested that portions of the evidentiary file in question might be “privileged” – or not subject to disclosure. Judge Kinder ordered her to produce all potentially privileged documents for his review to determine whether they could be disclosed.

Foster consulted Kaczmarek about the file’s contents, according to an email highlighted in the Velis-Merrigan report. Among other items, Kaczmarek noted the “mental health worksheets” found in Farak’s car, which had not been released. But in a memo to Judge Kinder the next week, Foster said she reviewed the file, and said every document in it had already been disclosed.

‘Fishing expedition’

“This is merely a fishing expedition,” Foster wrote in another filing. “There is nothing to indicate that the allegations against Farak date back to the time she tested the drugs” in Penate’s case. Judge Kinder denied Ryan’s motion. He also denied Penate’s motion to dismiss the case, saying there was no evidence that Farak’s misconduct extended to his case.

Penate was convicted in December 2013 and sentenced to serve five to seven years. Foster, now general counsel at the Massachusetts Alcoholic Beverages Control Commission, and Kaczmarek, now a clerk magistrate in Suffolk Superior Court, declined to comment for this story. Months after Farak pleaded guilty in January 2014, Ryan filed a motion on behalf of another client to see the evidence. Foster and another assistant attorney general assented to that motion. Ryan finally viewed the file in the attorney general’s offices in October 2014. As he leafed through three boxes of evidence, he found the substance abuse worksheets and diaries.

"It would be difficult to overstate the significance of these documents,” Ryan wrote to the Attorney General’s Office two days later. State prosecutors hadn’t provided this evidence to other district attorneys’ offices contending with the Farak fallout, either.

Two weeks after Ryan’s discovery, the Attorney General’s Office shipped nearly 300 pages of previously undisclosed materials to local prosecutors around the state. “Not only did they not turn these documents over, but I wasn’t aware that they existed,” said Frank Flannery, who was the Hampden County assistant district attorney assigned to appeals following Farak’s arrest. “

At the very least, we expected that we would get everything they collected in their case against Farak.” Flannery, now in private practice, said the substance abuse worksheets are “clearly relevant” to defendants challenging Farak’s analysis. Four months after Ryan found the worksheets, Judge Kinder compelled release of additional drug treatment records, which indicated Farak used a variety of drugs that she stole from the lab for years.

Penate and other defendants are asking see all of Foster’s emails regarding Farak and other materials relating to the handling of evidence in the chemist's case. A hearing on their motions is scheduled next month.