Parents accused of killing their 4-year-old daughter by overmedicating her with prescription drugs have asked a judge in Massachusetts to dismiss murder charges.

Lawyers for Carolyn and Michael Riley argued Monday that the grand jury that indicted the Rileys did not have a medical report from a prosecution expert. That expert acknowledges that Rebecca Riley had pneumonia when she died in December 2006. The defense contends that the girl died of pneumonia, not a drug overdose.

But prosecutors say the grand jury was told that the child appeared to be gravely ill in the days before her death. They say 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.

Judge Charles Hely did not immediately rule.