GIST: "It's been almost three years since former Amherst state lab chemist Sonja Farak pleaded guilty to evidence tampering and other crimes, but the scope of her wrongdoing, and when it started, has yet to be determined. Defense lawyers and their clients will be in front of Judge Richard J. Carey on Monday in Hampden Superior Court for a a multi-day hearing aimed at narrowing in on Farak's misdeeds. Carey is assigned to all the Farak-related cases and has said the hearings will address three major areas of concern. Those are: the scope and implications of Sonja Farak's misconduct; the overall integrity of the whole lab; the allegations of prosecutorial misconduct related to the non-disclosure of exculpatory evidence; Among those testifying at the hearing will be other chemists who worked at the now-closed Amherst lab, where most of the drugs were tested for use in Western Massachusetts prosecutions. State law requires prosecutors present evidence that drugs were tested for identification and quantity. In January 2014, Farak, of Northampton, was given an 18-month jail sentence.........The upcoming hearings are being held in connection with a group of defendants' motions to withdraw guilty pleas or have a new trial. Some defense lawyers want a determination that cases dating back to the onset of Farak's drug use while she worked for the state lab should be looked at anew for new trials or withdrawal of guilty pleas. Carey said in a previous hearing he wants to know why Farak's mental health care records -- found in Farak's car when she was arrested for drug thefts from the lab in Amherst in January 2013 -- didn't come to light until the fall of 2014. They came to light only after lawyer Luke Ryan was finally allowed to inspect evidence. Defense lawyer Luke Ryan said Levon Johnson's bail should be reduced in a cocaine trafficking case because the drugs were tested at the now closed and discredited Amherst drug lab. Defense lawyers have said the state's withholding of the records is prosecutorial misconduct. A report released in May concluded there was no evidence of prosecutorial misconduct or obstruction of justice by the assistant attorney general or state police officers in matters related to the Farak investigation. The report was prepared by Special Assistant Attorney General Peter J. Velis and special Northwestern Assistant District Attorney Thomas Merrigan. Farak began using drugs from the Amherst lab where she worked as early as late 2004 or early 2005, according to court documents released in May. An interim report by state Assistant Attorney General Thomas Caldwell said, "Ms. Farak began using controlled substances regularly in the last quarter of 2004; Ms. Farak was under the influence of controlled substances during a vast majority of her working hours from the last quarter of 2004 to her removal from the lab on Jan. 18, 2013." Earlier this year Farak testified under an immunity agreement before a grand jury investigating failures in the state crime lab. Caldwell wrote that she testified "about her extensive drug use; her siphoning of drugs from the lab's standards, which were used to test drug samples, from police-submitted samples of drugs, which were intended to be tested for evidentiary purposes in pending criminal cases, and from other chemists' samples; and her manufacturing in the lab of crack cocaine for her own personal use." Farak testified at that grand jury she first started using methamphetamine from the lab in late 2004 or early 2005. She said he enjoyed the "positive side effects" of the drug. She began to use it multiple times a day. Not taking the drug resulted in severe lethargy, irritability and lack of productivity and focus, to the point where she would have to call out sick."