Mental-health proceedings, attorney changes and repeated delays preceded Heather O’Neill’s negotiated resolution of a case once charged as attempted homicide.
MERRILL, Wis. — What began in June 2023 as an attempted homicide prosecution against a Wisconsin mother took more than three years to reach its final form, passing through bond disputes, a mental-illness plea, forensic review and attorney problems before Heather O’Neill accepted two felony child neglect counts.
O’Neill, 56, pleaded no contest July 31 to neglecting a child resulting in great bodily harm and neglecting a child resulting in emotional damage. Lincoln County Circuit Judge Ann Knox-Bauer placed her on probation for 9 1/2 years under a joint sentencing recommendation submitted by prosecutors and the defense. The resolution removed the original attempted first-degree intentional homicide charge from the case and ended the need for a trial on whether O’Neill intended to kill her teenage son during a medication overdose reported in 2023.
The prosecution’s timeline began on June 20, 2023, with a 911 call from O’Neill’s Merrill home. According to the criminal complaint, she told dispatchers that she had given herself and her 16-year-old son an overdose. She identified medications that included trazodone, sleep aids and sedatives. Emergency responders transported the teenager for treatment. At the hospital, he suffered a seizure, stopped breathing and required a breathing tube. He survived the medical crisis.
Investigators said O’Neill made statements suggesting the overdose was intentional. She described herself as exhausted by 16 years of what she characterized as her son’s violent tantrums and told police she wanted the situation to be “over for both of us.” Authorities said the teenager has autism and limited communication skills. The criminal complaint also described a note investigators found at the home in which O’Neill expressed despair about her life and resentment toward the demands of caring for her son.
The search produced medication evidence as well. Police reported finding multiple prescription bottles that they believed should not have been empty, together with partial bottles and over-the-counter medications. On June 22, prosecutors filed charges that included attempted first-degree intentional homicide, first-degree recklessly endangering safety and resisting or obstructing an officer. A judge initially set O’Neill’s cash bond at $100,000, placing the case on a path toward potentially severe punishment if the most serious allegation were proven.
The first major procedural milestone came in November 2023. After a preliminary hearing, Circuit Judge Robert Russell found probable cause that a felony had been committed and ordered O’Neill to stand trial. Her bond was later reduced to $25,000, but local reporting showed that she remained jailed. The court process then stretched far beyond the first year, with the case moving through changes in legal strategy and representation rather than directly to trial.
Representation became one source of delay. O’Neill’s first attorney withdrew from the case in late 2024 at her request. Court officials then spent months looking for an attorney who could take the appointment. John H. Wallace III became her lawyer in March 2025. The change came as the defense was preparing to shift the case toward questions about O’Neill’s mental state at the time of the alleged conduct.
On May 30, 2025, O’Neill changed her plea to not guilty by reason of mental illness. The prosecution did not object to the change, and the court ordered a psychiatric examination by the Wisconsin Forensic Unit. The examiner’s report was filed in December 2025. The defense later indicated that O’Neill wanted a second evaluation, and in May 2026 the court directed the original examiner to review her previous medical records. The proceedings kept mental-health issues at the center of the case for more than a year.
The available public reporting does not show that those evaluations produced a final judicial finding that O’Neill met Wisconsin’s legal standard for lack of responsibility because of mental illness. Instead, the case moved toward negotiation. That distinction matters because a plea of not guilty by reason of mental illness can raise questions different from whether a defendant has a diagnosis or has received mental health treatment. The final resolution did not require a jury to decide those issues.
Another disruption arrived shortly before the plea agreement. Wallace failed to appear for two consecutive hearings in July 2026, according to court minutes reported by Wausau Pilot & Review. Court staff were unable to reach him, and O’Neill told the court she had also been unable to contact her attorney. At a July 10 hearing, Knox-Bauer indicated that an order to show cause would be scheduled. Prosecutors, however, said they had communicated with Wallace about the possibility of resolving the case.
Those discussions produced a negotiated plea filed July 29. O’Neill returned to court two days later, entered no-contest pleas to the two amended neglect charges and was sentenced during the same proceeding. The original homicide and reckless-endangerment allegations were no longer the offenses on which she faced punishment. A misdemeanor obstruction charge was dismissed but read in, meaning the sentencing judge could consider the conduct connected to it.
The sentence reflected the negotiated nature of the resolution. On the neglect count involving great bodily harm, Knox-Bauer imposed and stayed 7 1/2 years of initial confinement and five years of extended supervision. O’Neill instead began 9 1/2 years of probation. On the emotional-damage count, the court ordered a concurrent seven years of probation and imposed and stayed five years in prison followed by five years of extended supervision. The stayed sentences provide a potential prison consequence if O’Neill’s probation is revoked.
O’Neill also received 1,138 days of credit for time already spent in custody, slightly more than three years. Records showed her address shifting from the Lincoln County Jail to a Merrill-area residence on the day she was sentenced. The length of that pre-sentence confinement helps explain how a prosecution filed in the summer of 2023 could conclude in 2026 with her release to supervision rather than a new period of immediate imprisonment.
The court paired that release with several restrictions. O’Neill may not contact her son unless he, his legal guardian and her probation agent agree. She cannot act in a parental, guardian or supervisory role for a child or an at-risk adult. The judge required a mental health evaluation and compliance with recommended treatment. O’Neill was also directed to prepare an apology letter for her son, which court records show was received Aug. 7.
Her son attended the July 31 proceeding but did not address the court. That silence left the sentencing record without a public victim statement from him. The public reporting reviewed for this article does not disclose his current living arrangement, medical condition or position on future contact with his mother. Those details have remained largely outside the public case even as his 2023 hospitalization formed the factual foundation for the charges.
The negotiated disposition closed the principal criminal case without resolving every question that might have been contested at trial. Jurors never weighed the prosecution’s original claim that O’Neill had acted with intent to kill, and they never heard a full defense based on mental illness. Instead, both sides agreed to resolve the matter through felony neglect pleas, years of supervision and stayed prison sentences.
The plea agreement closed the case without a jury ever deciding the attempted homicide allegation that defined its early stages. Instead, O’Neill’s criminal judgment rests on the two child neglect felonies she accepted in July. The original intent question therefore remains untested at trial, while the negotiated convictions and sentence now govern the legal consequences of the 2023 incident.
Author note: Last updated November 10, 2026.