The trial of Lindsay Clancy, a Massachusetts woman whom police charged in the deaths of her three children in January 2023, begins Monday.

July 20 (UPI) -- The trial of Lindsay Clancy, a Massachusetts woman whom police charged in the deaths of her three children in January 2023, begins Monday.

Clancy pleaded not guilty to the three counts of first-degree murder. Prosecutors say she strangled Cora, 5; Dawson, 3; and Callan, 8 months, after sending her husband out for takeout. She then attempted to take her own life, which left her with spinal cord injuries that mean she cannot walk.

Defense attorneys have said that, even if Clancy did kill the children, she is not criminally responsible for murder because of extreme mental health issues. Clancy struggled with postpartum depression and anxiety and heard voices telling her to kill herself and the children, her lawyers say.

Clancy, who worked as a labor and delivery nurse at Massachusetts General Hospital sought treatment for her mental health issues and was prescribed more than a dozen medications on and off over several months, The New York Times reported.

Her husband, Patrick Clancy, filed a lawsuit against her psychiatrist earlier this year, saying that no one monitored her reactions to the medications, realized how extensive her illness became or responded to her condition as it got worse.

Clancy herself has filed a personal injury lawsuit against her healthcare providers, saying they failed to properly diagnose or treat her condition, CNN reported.

In December 2022, Clancy admitted herself to a program for patients with postpartum depression. She later admitted herself to McLean Hospital, a residential psychiatric facility, for treatment and stayed there five days.

On Jan. 24, 2023, Clancy said she heard a male voice telling her that "she should die, that this is her last chance, and that her children would suffer if she was gone," The Times reported. She sent her husband out for takeout, strangled her three children and cut her wrists and neck and jumped from a second-story window.

While the defense says Clancy was a sick woman who tried many times to get help before an extreme mental health crisis, the prosecution says she acted with "deliberate, premeditated and extreme atrocity and cruelty." Before the trial, prosecutors filed a motion to include as evidence audio recordings of Patrick Clancy's 911 call when returned home and found his family.

Jurors will hear the 911 call and tour the Clancys' house, CNN reported.

The trial is expected to last six to eight weeks. If convicted, Lindsay Clancy faces life imprisonment without parole.

If the jury finds she is not criminally responsible, the court would likely start the legal process to have her committed to a state psychiatric hospital, CNN said.