The murder trial of a woman accused of beating her mother with a hammer before slashing her throat has ended in a mistrial.

After two days of deliberations in the Kirsten Lamb trial, jurors returned to the courtroom Friday afternoon telling Justice Paul Belzil they were hopelessly deadlocked and could not reach a verdict.

When the Belzil asked them to go back and try again, one juror broke down and began sobbing uncontrollably. Two other jurors also appeared upset.

Within minutes the jurors sent word back that they were not going to be able to reach an unanimous decision.

Belzil told the Crown and defence lawyers the jurors' stress levels were of grave concern to him and that it was his job to protect the jurors as well as the accused.

The lawyers pushed for a cooling-off period to let the situation settle down after the five-week trial.

But when the jurors rejected the offer, Belzil declared a mistrial.

"I'm going to declare a mistrial and discharge you and thank you for your patience," he said.

Lamb, 32, showed no emotion during the proceedings.

Lamb is charged in the November 2010 death of her 49-year-old mother Sandra Lamb who was found severely beaten and her neck slashed almost to the point of decapitation.  

During the trial the jury heard Kirsten Lamb, a diagnosed schizophrenic, and her sister were physically abused by their mother, who often smoked pot and used crystal meth and crack cocaine.

The murder trial began on Feb. 9 with the jury of six men and five women beginning deliberations Wednesday morning.

Lamb was sent back to Alberta Hospital Friday. A date will be set for the retrial next month.