BOSTON -- State prosecutors have already dismissed 8,000 drug cases touched by Amherst drug lab chemist Sonja Farak's misconduct. But Farak may have tampered with more cases than that, Attorney General Maura Healey wrote in a court brief in which she urged the court to consider dismissing additional cases.

Whether more drug defendants will have their cases dismissed is up to the Supreme Judicial Court, which will hear arguments May 8.

Farak was arrested in 2013 for stealing samples from the Amherst state drug lab to feed her own addiction. She pleaded guilty to evidence tampering and drug charges. District attorneys have agreed to dismiss more than 8,000 drug cases, which include all the cases where Farak signed a certificate indicating that she tested the drug samples.

The American Civil Liberties Union and the Committee on Public Counsel Services, the public defender office, have asked for the dismissal of all cases involving drugs tested in the Amherst lab during Farak's tenure. The district attorneys oppose any more dismissals.

Healey's brief is significant because it acknowledges that Farak's misconduct directly touched more cases than prosecutors previously acknowledged when they agreed to the dismissals. Healey is urging the court to set up a process for identifying and considering the dismissal of additional cases.

The cases in question were tested in the Amherst drug lab between June 2012 and January 2013.

According to Healey's court brief, Farak said in testimony before a grand jury that she began to steal from other chemists' samples in the summer of 2012. That was around the same time Farak's co-workers started to see a change in her behavior, the co-workers testified in court.

According to court testimony, by the end of 2012, Farak was going into a safe and stealing drugs from samples that had not yet been assigned for testing, then manipulating the lab's assignment and inventory systems to avoid detection. Farak did not provide a comprehensive list of the samples she tampered with.

"These circumstances offer some evidence, beyond speculation, that between June of 2012 and January of 2013, Farak may have tampered with other chemists' samples before they were tested," attorneys for Healey's office wrote. "Because Farak did not identify those samples with particularity, and because her pre-testing misconduct may have compromised the reliability of any subsequent analysis by other chemists, all defendants who were convicted based upon drug evidence that was tested at the Amherst lab during the relevant time period should be granted relief."

Healey is suggesting a process identical to the one used in the earlier Farak cases, where district attorneys identify each case that was affected and decide whether to dismiss it.

Healey does not indicate how many cases were tested in the Amherst drug lab during this time period, although it is likely to be several hundred.

The Committee for Public Counsel Services said there are a total of 19,000 drug convictions that involved samples tested at the Amherst lab during Farak's tenure, from August 2004 to January 2013. That includes the 8,000 where Farak signed the certificate of analysis.

The Farak case is complicated by the fact that two former assistant attorneys general were found by a judge to have withheld important evidence related to the time frame in which Farak was using drugs. The two former assistant attorneys general - Anne Kaczmarek and Kris Foster - have been reported to the Board of Bar Overseers for misconduct.

The public defenders argue that the prosecutorial misconduct justifies the dismissal of all 19,000 convictions because it delayed the defendants' ability to challenge their convictions. Dismissing the additional cases, they say, will deter similar misconduct in the future.

The district attorneys argue that there is no reason to dismiss cases that were not directly affected by Farak. A blanket dismissal, they wrote in a court brief, "infringes too severely on the public interest in bringing guilty persons to justice."

Healey agrees with prosecutors that only cases touched by Farak should be dismissed.

Rebecca Jacobstein, an attorney for the Committee for Public Counsel Services, said while she is pleased Healey acknowledged the larger scope of Farak's misconduct, the public defenders still do not think Healey goes far enough by limiting the time frame to late 2012. The public defenders argue in a court brief that Farak's stealing of her colleagues' samples could have started before then.

The time frame laid out by Healey "was based on (Farak's) testimony, which was inaccurate and unreliable," Jacobstein said in an interview.

The SJC will also consider whether the attorney general's office should face sanctions and whether any additional measures are required to prevent future prosecutorial misconduct.

Healey said her office has already created a new internal ethics committee to answer questions and review policies related to ethics. Her office increased training on prosecutorial ethics and criminal discovery. It implemented a new policy to increase supervision and reporting in the "rare" cases when exculpatory evidence can be withheld. Her office also is helping to lead a Bar Association committee on conviction integrity programs.

"The Attorney General has been clear that the conduct of two line prosecutors during the previous administration was unacceptable and beneath the standards she has set for the office," said Healey spokeswoman Emalie Gainey in a statement. "AG Healey has been and will continue to be proactive in taking steps to make sure that it never happens again."

The public defenders are asking for financial penalties against the attorney general's office.