Annie Dookhan, a former chemist for the state of Massachusetts, was arrested at her home Friday, accused of lying about the results of drug tests and about her qualifications, the latest step in a scandal that has compromised thousands of criminal cases. Dookhan, 34, of Franklin, Mass., was arrested without incident by state police, the attorney general's office said. Dookhan faces two counts of obstruction of justice and one count of pretending to hold an advanced degree, officials said. Each obstruction count carries a maximum punishment of 10 years in prison; the credentialing charge carries a maximum penalty of one year in jail, if convicted. "Annie Dookhan's alleged actions corrupted the integrity of the criminal justice system," Atty. Gen. Martha Coakley said in a statement. A fair and effective justice system not only protects those directly involved in the courts, but the public's safety beyond it. The public deserves a criminal justice system that they can trust, and we are committed to holding those responsible for this breakdown accountable and fixing it moving forward. State officials have said that Dookhan tested more than 60,000 drug samples involving 34,000 defendants during her nine years at the Hinton State Laboratory in Jamaica Plain. At least 20 drug defendants have already been freed or seen other actions -- such as bail reduction or sentence suspension -- because the evidence in those cases depended on work by Dookhan. Officials have also estimated that more than 1,100 inmates are in prison in connection with cases on which Dookhan worked. Attorney David E. Meier has been named by Gov. Deval Patrick to look at the implications of the scandal on the state's criminal justice system. "I think that all of those who are accountable for the impact on individual cases need to be held accountable," Patrick told reporters Thursday. Several years ago, other lab workers began to question Dookhan's work, but no action was taken. According to the attorney general's office, officials began their investigation in July after more allegations emerged of improprieties at the state laboratory where Dookhan carried out drug tests from across the state. According to State Police reports obtained by the Boston Globe, Dookhan has admitted improperly removing drug evidence from storage, forging colleagues" signatures, and not performing proper tests on drug evidence for "two or three years." Dookhan told State Police she recorded drug tests as positive when they were negative "a few times" and sometimes tested only a small sample of the drug batch that she was supposed to analyze, the newspaper reported. I messed up. I messed up bad. It's my fault," she told state troopers who visited her Franklin home on Aug. 28. She said that she acted alone, saying, "I don't want the lab to get in trouble." Dookhan is accused of lying about the integrity of drug evidence she analyzed in two instances and allegedly lying under oath about having a master's degree in chemistry, the attorney general's office said in a statement. According to the charges, Dookhan tested samples in 2011 and determinedthat they were cocaine. Further testing in the last week showed that was false. Dookhan also testified in court that she had a master's degree in chemistry from the University of Massachusetts. Officials said that she holds no such degree nor is there any evidence she ever enrolled in a post-graduate class. 5 dead, 4 more hurt in Minneapolis shooting rampage Rocky evidence conjures image of water flowing freely on Mars