The court imposed years of supervision and stayed prison time after Heather O’Neill entered no-contest pleas in Lincoln County.
MERRILL, Wis. — Heather O’Neill walked out of custody after more than three years behind bars, but the sentence resolving the Wisconsin mother’s criminal case placed extensive limits on her contact with her son, her ability to supervise vulnerable people and her freedom for nearly the next decade.
The 56-year-old Merrill woman was placed on probation for 9 1/2 years after pleading no contest July 31 to two amended felony counts of neglecting a child. The sentence brought an end to a prosecution that started with an attempted first-degree intentional homicide charge after O’Neill reported giving her 16-year-old son multiple medications in June 2023. Judge Ann Knox-Bauer adopted a joint recommendation from prosecutors and the defense, imposing prison terms but staying them while O’Neill remains on probation and follows the conditions set by the court.
Those conditions make the sentencing outcome more complicated than a simple decision between prison and release. O’Neill may not have contact with her son unless the son, his legal guardian and her supervising agent all consent. She is barred from serving in a parental, guardian or supervisory role for any child or at-risk adult. She must undergo a mental health evaluation and follow recommended treatment. She was also required to write an apology to her son, and court records show that a letter was filed Aug. 7.
The potential prison consequences remain substantial. On the count alleging neglect resulting in great bodily harm, Knox-Bauer imposed and stayed 7 1/2 years of initial confinement followed by five years of extended supervision. O’Neill received 9 1/2 years of probation on that count. A second neglect count, involving emotional damage, brought a concurrent seven-year probation term and a stayed sentence of five years in prison followed by five years of extended supervision. If her probation is revoked, the stayed sentences could become consequential to how much time she ultimately spends incarcerated.
O’Neill received credit for 1,138 days already spent in custody, more than three years. Local court records showed that her listed address changed from the Lincoln County Jail to a residence in the Merrill area on the day of sentencing. Her son attended the hearing but declined an opportunity to speak, according to court minutes. The public record provides no statement from him explaining his view of the plea agreement or sentence, and reporting reviewed for this article does not describe his current circumstances in detail.
The restrictions imposed in 2026 grew from a medical emergency on June 20, 2023. According to the criminal complaint, O’Neill called 911 and said she had given both herself and her teenage son an overdose. Authorities said she identified the substances given to the boy as including trazodone, sleep aids and sedatives. The teenager, who has autism and was described by investigators as having limited communication skills, was taken for emergency medical treatment after responders arrived.
His condition became critical at the hospital. Police and court reporting said the teenager suffered a seizure, stopped breathing and was intubated. He ultimately survived. Investigators said O’Neill told officers she was overwhelmed by what she described as years of violent tantrums and physical aggression. At the hospital, according to court records, she said she had “snapped” after 16 years and wanted the ordeal to be “over for both of us.” The descriptions of the son’s behavior came from O’Neill and were not independently established in the court reporting.
A search of the home gave investigators additional evidence they cited in the original prosecution. Authorities said they recovered prescription bottles that appeared to have been emptied before they should have been, along with other medications. They also found a note attributed to O’Neill describing despair about her life and her relationship with her child. Police treated the medication evidence, the note and O’Neill’s reported statements as supporting an intentional act, and prosecutors initially charged her with attempted first-degree intentional homicide and first-degree recklessly endangering safety, along with obstruction.
That original charging decision carried the possibility of a dramatically different outcome. When O’Neill first appeared in court in 2023, a judge set a $100,000 cash bond. It was later reduced to $25,000. At a preliminary hearing that November, a judge found enough evidence for the felony case to move forward. O’Neill remained jailed as the proceedings continued, and what began as a relatively direct prosecution became a lengthy case involving changes in attorneys, questions about mental illness and repeated delays.
By May 2025, O’Neill had changed her plea to not guilty by reason of mental illness. The court ordered a psychiatric examination through the Wisconsin Forensic Unit, and an examiner’s report was filed in December. The following year, the defense sought further consideration of her mental condition, including review of earlier medical records. Those proceedings did not result in a publicly reported trial or judicial finding on the original attempted homicide allegation. Instead, prosecutors and the defense eventually moved toward a negotiated resolution.
The representation issues added another layer of delay. O’Neill’s first lawyer withdrew in late 2024 at her request. Court staff then spent months trying to secure new counsel before John H. Wallace III was appointed in March 2025. In July 2026, Wallace missed two consecutive hearings, according to court minutes. Court staff reported being unable to reach him, while O’Neill also said she had been unable to make contact. Prosecutors told the court they had nevertheless communicated with Wallace about a possible agreement.
A negotiated plea was filed July 29. Two days later, O’Neill pleaded no contest to the amended neglect charges and was sentenced. A misdemeanor obstruction charge was dismissed but read in, allowing the judge to consider that conduct without entering a judgment on the dismissed allegation. The joint sentencing recommendation meant the prosecution and defense approached the court with the same proposed disposition, and Knox-Bauer accepted it.
The final charges focused on the harm to O’Neill’s son rather than requiring a trial over whether she intended to kill him. One neglect count addressed great bodily harm and the other emotional damage. Because the attempted homicide allegation was replaced through the plea agreement, no jury was asked to decide that original accusation. The resolution therefore narrowed both the legal questions and the possible punishment while still leaving O’Neill subject to felony sanctions and a long period of court supervision.
The no-contact provision is among the sentence’s most significant practical consequences. It puts the decision about any future interaction partly outside O’Neill’s control by requiring multiple parties to consent. The separate prohibition on supervising children or at-risk adults also extends the order beyond her relationship with her son. Combined with the mental health requirements, the terms show that the court’s sentence is built around continued oversight rather than an unconditional return to ordinary life after her release from jail.
For the son, the public record remains comparatively sparse. Authorities documented the severe medical crisis he experienced in 2023 and later reported his survival. Three years later, he sat in the courtroom for the final plea and sentencing but chose not to make a statement. Nothing in the records reviewed for this article indicates that the no-contact order has since been modified or that he has consented to communication with O’Neill.
Whether O’Neill and her son have any future contact will not be hers alone to decide. The sentencing order requires consent from her son, his legal guardian and her supervising agent before communication can resume. He attended the sentencing but did not speak publicly, leaving his position on the plea, sentence and any future relationship outside the public record.
Author note: Last updated November 10, 2026.