SANTA ANA (AP) — A Southern California housewife who claimed she suffered from postpartum psychosis when she ran over her newborn infant with the family Volvo in 1987 is asking a jury to declare her legally sane after more than two decades of court-ordered medical supervision.

Sheryl Lynn Massip, now 46, will be in court Thursday in her bid to free herself of the last legal vestiges of an emotionally charged case and explosive outcome that captivated the nation and spurred debate about the limits of a “baby blues” legal defense.

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If she prevails, the former beautician will no longer have to attend therapy sessions or undergo treatment programs.

Massip was convicted of second-degree murder after a two-month trial by a jury who also found her sane.

But Orange County Superior Court Judge Robert Fitzgerald stunned the court during a sentencing hearing when he set aside the jury verdict, reduced the charge to voluntary manslaughter and found Massip not guilty by reason of insanity.

Massip underwent a psychiatric evaluation and was placed under court-ordered medical supervision without serving any time in prison or a state mental hospital.

Massip does not deny she killed her 43-day-old son on her 23rd birthday, but maintains she was mentally ill with postpartum psychosis at the time. She has since remarried, has a 14-year-old daughter, and goes by the name Sheryl Lynn Smith.

During her second-degree murder trial, the devout Lutheran and housewife testified that she thought the child was a doll when she placed him under the wheel of the family car and that voices ordered her to put him out of his misery.

She told jurors the baby was crying up to 18 hours a day and vomited constantly but she got no help from her husband and was exhausted. She said she began having nightmares about committing suicide and began hearing voices.

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“They said, ‘Put him out of his misery.’ It was over and over,” she said at trial.

Massip testified that on April 29, 1987 she lost her final toehold on sanity: She threw the baby in front of a passing car, but when the driver swerved, she picked the infant up and returned home.

There, she recalled striking him in the head in the garage with some type of tool until she put finally put the 6-week-old face up under her car’s left front tire and drove over him.

She dumped the body in a trash can near her home and told her husband a stranger had snatched the baby.

She eventually confessed at the police station after her husband noted inconsistencies in her story.

Friends and relatives who also testified in 1988 described Massip as a glowing mother-to-be who transformed into a paranoid zombie after becoming a mother.

Massip’s mother, Pat Delano, told jurors her daughter called the baby a “demon” and admitted she could hear him screaming in her head even when the infant was not around. On one occasion, Delano said, Massip had a seizure and showed up on her doorstep sobbing so much that her shirt was soaked with tears.

In 2008, Massip’s attorney Milton Grimes told The Orange County Register that his client was fully recovered and had been a perfect patient, never missing a therapy session or treatment. He said administrators of the court-ordered program agreed his client no longer needed supervised care.

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