Watch Live: Lindsay Clancy trial judge rules TikTok user can't testify

Lindsay Clancy's trial is back underway Wednesday in Massachusetts with the cross-examination of a forensic psychologist who testified that Clancy said she heard a voice ordering her to kill her children.

Dr. Paul Zeizel was one of several witnesses who testified for the defense on Tuesday. He was back on the stand this morning in Plymouth Superior Court. Another full day of testimony is expected.

You can watch the trial live on CBS News Boston in the embedded video or on YouTube when court is in session.

Zeizel met with Clancy in the hospital in early February 2023, shortly after the murders of her three children, 5-year-old Cora, 3-year-old Dawson, and 8-month-old Callan, in their Duxbury home on Jan. 24, 2023 .

On Wednesday, he started by testifying about steps Clancy took to treat her mental health in the months before the murders. He said she sought help in late 2022 for depression and psychotic symptoms of disassociation.

"She felt that her brain was damaged, she felt that she should kill herself and she was never going to get any better," Dr. Zeizel testified. "Her concern was that when people could hear her thoughts, her children would be removed from her care."

Dr. Zeizel also testified that she called the suicide hotline twice in December but did not receive any help. He said she continued experiencing unrelenting intrusive thoughts and voices in her head after being discharged from McLean Hospital in January.

"They were getting worse and they were telling her to kill herself," he said.

"My opinion is that she did have indeed a mental disease," he said. "She was unable to conform her behaviors to the rule of law, and she had no appreciation for the wrongfulness of her act."

During cross-examination, prosecutor Shanan Buckingham asked how Dr. Zeizel found out that Clancy was hearing voices. He said he spoke to other people, including a chaplain, who said she reported hearing voices. Buckingham said that's not what she was telling doctors before the murders.

"You're aware that when she described intrusive thoughts, she never referred to them as a voice telling her to kill herself, did she?" Buckingham asked.

Clancy has pleaded not guilty to first-degree murder but admits to killing her children. Her attorney, Kevin Reddington, has argued Clancy should not be held criminally responsible because she was overmedicated and suffering from postpartum psychosis .

Prosecutors said she planned the murders before faking a suicide attempt that left her paralyzed and in a wheelchair.

If Clancy is convicted of first-degree murder, she faces life in prison without parole. If the jury finds that she was not criminally responsible for the deaths of her children, she will be sent to a state psychiatric hospital in Massachusetts.