The boy required emergency breathing support in 2023 before a prosecution against his mother ultimately narrowed from attempted homicide to neglect.
MERRILL, Wis. — A 16-year-old boy survived after suffering a seizure and losing the ability to breathe during a 2023 medication overdose, setting in motion a Wisconsin criminal case that ended three years later with his mother pleading no contest to child neglect and receiving lengthy probation.
The teenager’s medical emergency was at the center of the prosecution of Heather Joy O’Neill, now 56. Authorities initially accused O’Neill of attempted first-degree intentional homicide after she called 911 on June 20, 2023, and reported that she had given both herself and her son an overdose. By July 2026, however, prosecutors and the defense had negotiated a resolution involving two felony neglect counts. O’Neill received 9 1/2 years of probation, while substantial prison sentences were imposed but stayed.
According to the criminal complaint, O’Neill told emergency dispatchers that her son had received several types of medication, including trazodone, sleep aids and sedatives. Responders found the teenager alive and arranged emergency care. His condition deteriorated after he reached a hospital. He suffered a seizure and stopped breathing, requiring medical staff to intubate him. Later reports said he recovered, though authorities did not publicly release a detailed account of his longer-term medical condition.
The boy has autism and was described in court records as having limited communication skills. Investigators said O’Neill attributed her actions to years of what she described as violent tantrums by her son. At the hospital, she told police that she had “snapped” after 16 years and said he had hit her. She also said she wanted the situation to be “over for both of us.” Those claims about the boy’s conduct came from O’Neill’s reported statements and should not be treated as independent findings about him.
O’Neill’s comments were not the only evidence cited by authorities. Investigators searching the Merrill home said they found several medication bottles that appeared to have been emptied earlier than expected, as well as other prescription and nonprescription drugs. Police also recovered a note attributed to O’Neill that expressed despair about her life and her relationship with her son. The note included harsh language about the burden she said she felt, but its central significance to investigators was the hopelessness and intent they believed it reflected.
Prosecutors responded by filing a case that initially treated the incident as an attempted killing. O’Neill was charged with attempted first-degree intentional homicide, first-degree recklessly endangering safety and resisting or obstructing an officer. At her first court appearance, a judge set a $100,000 cash bond. The attempted homicide count carried the most serious potential consequences and framed the prosecution for much of its early life.
That accusation survived an initial judicial review. During a November 2023 preliminary hearing, a circuit judge found probable cause that a felony had been committed and ordered O’Neill to continue through the criminal process. Her cash bond was later reduced to $25,000. Despite the reduction, local reporting showed that she remained incarcerated while the case proceeded, eventually accumulating more than three years in custody before sentencing.
The legal issues grew more complex over time. O’Neill’s first lawyer withdrew in late 2024 at her request, and the court had difficulty finding replacement counsel. Attorney John H. Wallace III was ultimately appointed in March 2025. Two months later, O’Neill changed her plea to not guilty by reason of mental illness, opening a new phase that focused on forensic evaluation rather than an immediate trial on the prosecution’s evidence.
A Wisconsin Forensic Unit examiner was assigned to evaluate O’Neill, and a report was filed in December 2025. The defense later sought additional examination, while the court asked that earlier medical records be reviewed. Those proceedings continued into 2026. Public reports do not show that the mental-health litigation resulted in a final ruling absolving O’Neill of criminal responsibility. Instead, the parties ultimately negotiated amended charges that allowed the case to be resolved without trial.
The final weeks brought another series of procedural problems. Wallace missed two consecutive hearings in July 2026, and court staff could not reach him, according to court minutes. O’Neill also reported difficulty contacting her attorney. The judge discussed an order to show cause, but prosecutors said they remained in communication with Wallace about a potential agreement. A negotiated plea was filed July 29, signaling that the long-running case was close to a conclusion.
On July 31, O’Neill pleaded no contest to two felony charges of neglecting a child. One count alleged neglect resulting in great bodily harm, tying the resolution directly to the serious medical consequences suffered by her son. The other involved emotional damage. A misdemeanor obstruction allegation was dismissed but read in for sentencing purposes. The changed charges meant the case ended without a jury deciding whether O’Neill possessed the intent required for the original attempted homicide count.
Judge Ann Knox-Bauer accepted a joint sentencing recommendation. For the great-bodily-harm count, the judge imposed and stayed 7 1/2 years of initial confinement followed by five years of extended supervision and placed O’Neill on probation for 9 1/2 years. A second sentence of five years in prison and five years of extended supervision was also imposed and stayed, paired with seven years of concurrent probation. The stayed terms leave prison available if O’Neill’s probation is later revoked.
The court credited O’Neill with 1,138 days she had already spent in custody. Records showed that she left the Lincoln County Jail for a Merrill-area residence on the day of sentencing. The result allowed her to remain out of prison immediately, but it placed her under court supervision for years and subjected her to restrictions directly connected to the relationship at the center of the case.
Most notably, O’Neill cannot contact her son unless he, his legal guardian and her supervising agent agree. She is prohibited from acting as a parent, guardian or supervisor for any child or at-risk adult. The sentence also requires a mental health evaluation and completion of recommended treatment. The judge ordered an apology letter to her son, and court records show the letter was received Aug. 7.
The son returned to the public record at the sentencing hearing in a markedly different role from the critically ill teenager described in the 2023 complaint. He attended court but chose not to speak. No public statement from him about his mother’s plea, the probation sentence or the no-contact condition was identified in the reporting reviewed. His decision left the court record focused primarily on the lawyers, the judge and the procedural terms of the agreement rather than his own account.
His survival nevertheless remained the central fact shaping the case. The prosecution that began with allegations of intentional homicide ultimately concluded with charges defined by the harm caused to him. The plea did not produce a trial over O’Neill’s original intent, but it did lead to felony sanctions tied to both the physical and emotional consequences alleged by prosecutors.
Long-term court oversight, rather than another immediate prison term, is now the central consequence of the case. O’Neill must comply with mental health requirements, cannot supervise children or at-risk adults and faces strict limits on contact with her son. Those restrictions will shape the years ahead under probation, with the stayed prison terms remaining available if she violates the conditions imposed by the court.
Author note: Last updated November 10, 2026.