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A woman accused of shooting her two teenagers called herself "a failure" because she didn't succeed at committing suicide after killing her children, a psychiatrist testified Monday.

Dr. Eldra Solomon testified in the trial of Julie Schenecker in Hillsborough County Court. The doctor was called to the stand by the defense team, which is trying to prove the 53-year-old was insane in January 2011 when she shot her 16-year-old daughter and 13-year-old son.

Schenecker is charged with two counts of first-degree murder. The state is not seeking the death penalty.

Solomon told the jury that she reviewed all of Schenecker's medical records and spent some 20 hours with her following the slayings.

She detailed how Schenecker was molested by a neighbor when she was 7, and how she had thought about suicide since she was 12 -- and tried to commit suicide twice. Schenecker had been diagnosed with bipolar disorder with psychotic features on many different occasions, by several doctors, throughout her life.

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Schenecker irrationally thought she had a brain tumor, that her daughter was also bipolar and that her son would be molested, the doctor said. She also talked for months to her therapist about wanting to get pregnant at the age of 49 -- and give up the baby for adoption.

Solomon said "sane people don't kill their children."

"I think without a doubt she was insane at the time of the shooting and during the week prior to the shooting," she said.

Moments before killing Beau in the family's minivan, Schenecker noted a pile of laundry on the washing machine and told herself that she needed to wash Beau's soccer uniform for an upcoming game.

"Here's a woman who's about to kill him and it doesn't make sense," said Solomon. "She's psychotic."

While cross-examining Solomon late Monday morning, prosecutors pointed out that in some records from 2011, nurses and doctors saw no signs of psychosis. Prosecutors have said Schenecker wrote plans for the killings in a journal and bought a gun days before the slayings.

Solomon also testified for the defense that Schenecker went off her medication in the six months prior to the shootings and then went on a "downward spiral" of depression and psychosis.

Solomon said Schenecker intended to kill herself after shooting her kids. She had a three-part plan, Solomon said: sit in the car and breathe carbon monoxide, take pills and then shoot herself. After shooting her children, Schenecker reloaded her gun and then took the pills -- but the pills knocked her out for the night.

"She said she was very angry at herself because she failed," Solomon said. "She was very upset because she didn't succeed at killing herself."

Schenecker awoke the next morning in the family's home, groggy and shaky. Officers arrived soon after -- Schenecker's family had called police and asked them to check on her because they were worried about her mental health.

While interviewing Schenecker in jail, Solomon said the military mom fluctuated in lucidity. At one point, she was angry that she couldn't attend her children's funeral. At another point, she thought her children were still alive.

On Friday, Schenecker yelled, "Liar!" at another psychiatrist who was testifying that he had told her not to drink while taking drugs to control her bipolar disorder.

Judge Emmett Battles immediately stopped the hearing, ordered the jury out and admonished Schenecker, telling her she would be restrained if she had another outburst.