McKinney, Texas ? A judge declared a mistrial Saturday in the murder trial of a woman accused of fatally cutting the arms off her 10-month-old daughter.

Jurors deadlocked during the fourth day of deliberations in the case of Dena Schlosser, 37, who pleaded not guilty by reason of insanity.

“Any further deliberations would be pointless,” the jury said in a note to Judge Chris Oldner after nearly nine hours of discussions Saturday.

Police arrested Schlosser in November 2004 after finding her baby Margaret, known as Maggie, dying in her crib, and Schlosser covered in blood, holding a knife and listening to a hymn.

The prosecution argued that she knew what she was doing, showing the jury grisly photos of the dead baby and emphasizing several witnesses’ observations of Schlosser as a healthy, seemingly sane mother.

But psychiatrists testifying for the defense told jurors of multiple psychotic episodes Schlosser detailed to them. One doctor said Schlosser told him she felt commanded by God to cut off Maggie’s arms, followed by her own limbs and head. Schlosser had a deep cut on her shoulder when police found her.

The jury said on the second day of deliberations that it was deadlocked, but the judge ordered them to continue.

Jurors requested numerous rereadings of testimony, with one juror even asking Oldner to define the term “deliberation” and the precise role of a juror.

After her arrest, Schlosser was diagnosed with manic depression and declared mentally incompetent to stand trial. But in May, after doctors treated her, a judge found she was competent.