Lawyers for Carolyn and Michael Riley said that because the grand jury that indicted the couple did not have the report, they were given "inaccurate" information on the cause of Rebecca Riley's death.
But prosecutors said they have always argued — and did so before the grand jury — that Rebecca appeared gravely ill in the days before her death in December 2006. They said the grand jury was also told that the Rileys ignored pleas to take her to a doctor and instead gave her an overdose of medication she had been prescribed for attention-deficit hyperactivity disorder.
The move to dismiss the charges comes days before the Rileys' trial is slated to begin. Jury selection is scheduled to begin Wednesday in Brockton Superior Court.
Judge Charles Hely did not immediately rule on the defense motion.
The defense contends that the girl died of a rapid-onset form of pneumonia, not a drug overdose.
A state medical examiner found that Rebecca died of a combination of Clonidine, a blood pressure medication the girl had been prescribed for attention deficit hyperactivity disorder; Depakote, an antiseizure and mood-stabilizing drug prescribed for bipolar disorder; and two over-the-counter drugs, a cough suppressant and an antihistamine. The amount of Clonidine alone in Rebecca's system was enough to be fatal, the medical examiner said.
But Carolyn Riley's lawyer, Michael Bourbeau, said a separate medical report prepared for prosecutors and turned over to the defense last week bolsters the defense claim that Rebecca died of fast-moving pneumonia.
"If the cause of death is pneumonia, it is not homicide," Bourbeau said, urging the judge to dismiss the murder indictment.
Assistant District Attorney Frank Middleton said the grand jury, which indicted the Rileys in March 2007, was told that Rebecca appeared to be gravely ill in the days before her death. He said the grand jury was also told that the Rileys ignored pleas from two people who lived with them to take the girl to a doctor.
"Letting your child die and not getting her medical treatment is murder in the Commonwealth of Massachusetts," Middleton said.
In her report, Dr. Sara Vargas said Rebecca had acute pneumonia and sepsis, or widespread infection, which were "adequately severe to explain death in this case."
She added, however, that the medications Rebecca was taking "may have caused the bacterial pneumonia and sepsis or contributed to their severity" by predisposing the girl to infection.
Middleton said Vargas does not declare a cause of death in her report, but only says that Rebecca had pneumonia when she died.
Middleton said another state expert, a toxicologist, will testify that Rebecca had to be given twice her prescribed daily dose of Clonidine to reach the level of Clonidine in her blood when she died.
The girl had been diagnosed with ADHD and bipolar disorder by the time she was 3.
Her death inflamed a long-running debate in psychiatry over whether young children can accurately be diagnosed with bipolar disorder and whether they should be treated with powerful drugs used for adults.