Annie Dookhan, the former chemist at the state lab whose alleged mishandling of evidence has thrown the state’s criminal justice into turmoil, made a series of “tragic and terrible mistakes,” her defense attorney said today in a hearing in Suffolk Superior Court.

Attorney Nicolas Gordon argued for a one-year prison sentence, far less than the 5 to 7 years that the attorney general’s office is seeking.

“There is absolutely no malicious or black-hearted or evil criminal intent to be found anywhere in this case,” Gordon told Superior Court Judge Carol Ball.

Advertisement - Continue Reading Below

Assistant Attorney General Anne Kaczmarek argued that because of Dookhan’s “self-serving and selfish” intent and the widespread impact of her actions, she should get the longer sentence. She said Dookhan’s actions had weakened and created mistrust of the criminal justice system, and cost taxpayers hundreds of millions of dollars to rectify.

Prosecutors are also seeking five years of probation for Dookhan, 35, who attended today’s hearing, along with her father, and at one point broke into tears.

Ball said she would listen to the lawyers’ arguments and announce at the end of next week the maximum sentence that she would impose, if Dookhan decides to plead guilty.

Prosecutors have said Dookhan deliberately tampered with evidence so that substances would test positive for drugs. A review conducted at the request of Governor Deval Patrick found that her actions may have tainted more than 40,000 cases.

Hundreds of people have been released from state prisons and county jails due to questions about the evidence that was used to arrest or convict them. A state chemist’s certification that a substance seized by police is actually illegal drugs is a key foundation of a drug trial.

“The extraordinary damage is just incalculable,” Judge Ball said during the hearing.

Arguing for the more lenient sentence, Gordon said Dookhan was “a shell of her former self” whose “life has been destroyed.”

He said her husband has left her and is living with another woman and she has a 7-year-old disabled son with a medical condition. Dookhan is the center of the boy’s universe and she fears being separated from him, Gordon said. Tears rolled down Dookhan’s face as the lawyer spoke about her relationship with her son.

Gordon also argued that her motive had solely been to be a sterling employee.

“Her motivation is to be the hardest working and most prolific and most productive chemist that she can possibly be, and that’s how this whole mess begins,” he said. He described her actions as a “series of tragic and terrible mistakes.”

Judge Ball said she held the normally private lobby conference in public because “the events that brought us all here today have had such a serious impact on the criminal justice system” that it was important that everything about the case be “open and up front.”