OAKLAND COUNTY — Mosteller, 66, faced a maximum penalty of 15 years in prison for his role in the incident. Michigan Attorney General Dana Nessel announced a plea agreement with Mosteller in July 2026, stating that the conviction provides a measure of accountability for the family while acknowledging that no legal outcome can reverse the loss.

Thomas Cooper was from Royal Oak, Michigan, and was receiving treatment for sleep apnea and attention-deficit/hyperactivity disorder at the facility. The Oxford Center is an alternative healthcare facility located in the Detroit suburb of Troy that treats children with conditions including autism, ADHD, and autoimmune diseases through hyperbaric oxygen therapy.

An expert who viewed video of the case stated that Cooper squirmed enough to pull a sheet off a mattress inside the chamber, causing a spark of static electricity that became a flash fire in the oxygen-rich environment. James Harrington, an attorney supporting the family, described the horrific moments following the ignition. “The boy’s mother rushed toward the chamber when the fire ignited, burning her arm in an unsuccessful attempt to save her son,” Harrington said.

He further stated that the boy was burned alive in front of her. Records indicate Cooper's mother sustained burns on her arms and chest while attempting to open the hyperbaric chamber.

Four former Oxford Center employees were criminally charged in connection with Cooper's death. Tamela Peterson, the 58-year-old owner of the Oxford Center, faces charges of second-degree murder or involuntary manslaughter. Gary Marken, 65, who served as the primary management assistant at the center, also faces charges of second-degree murder or involuntary manslaughter.

Aleta Moffitt, 60, operated the hyperbaric chamber at the time of the incident and was charged with one count of falsifying medical records, as well as involuntary manslaughter and intentionally placing false medical information on a medical records chart. Peterson, Marken, and Moffitt have pleaded not guilty and are awaiting trial.

Prosecutors accused the Oxford Center of deliberately disregarding safety protocols set by the National Fire Protection Association and Sechrist Industries, the manufacturer of the hyperbaric chamber involved in the incident. While the U.S. Food and Drug Administration has cleared hyperbaric chambers to be marketed as safe and effective for 13 disorders, including severe burns, decompression sickness, and non-healing wounds, the prosecution argued that specific safety standards were ignored in this case.

Alona Sharon, an attorney, commented on the sentencing of Mosteller. “I expect his conduct will be stellar and I hope that he will be released at the 19-month mark,” Sharon said. Cooper's parents have also filed a civil lawsuit against the Oxford Center and Sechrist Industries seeking $100 million in damages.

Why It Matters

The sentencing of Jeffrey Mosteller marks the first criminal resolution in a case that exposed alleged safety failures at a facility treating vulnerable children. The incident resulted in the death of a 5-year-old boy and injuries to his mother, prompting both criminal charges against multiple staff members and a civil lawsuit. The case shows the regulatory and safety challenges associated with hyperbaric oxygen therapy, a treatment cleared by the FDA for specific medical conditions but used here for developmental disorders.

The outcome leaves three other defendants awaiting trial, including the facility owner and the operator of the chamber, ensuring that legal proceedings related to the death will continue. The civil suit seeking $100 million in damages against the center and the chamber manufacturer remains pending, indicating that financial and legal accountability efforts extend beyond the criminal convictions. The case serves as a focal point for discussions on safety protocol enforcement in alternative healthcare settings.

Timeline

In January 2025, Cooper died while undergoing treatment at the Oxford Center after a hyperbaric chamber caught fire and exploded. At the time of his death, Cooper was 5 years old. During the incident, Cooper's mother sustained burns on her arms and chest while attempting to open the hyperbaric chamber. Moffitt operated the hyperbaric chamber at the time of the incident.

In July 2026, Michigan Attorney General Dana Nessel announced a plea agreement with Mosteller. Nessel stated, “While no outcome can reverse this loss, it is my hope that this conviction provides a sense of justice to Thomas’s family.” She also stated, “A young child lost his life in a completely preventable tragedy because this defendant allowed an outdated device to operate in defiance of safety standards.” In September 2026, Mosteller was sentenced to 19 months in prison.

What's New

It was also reported that Peterson was charged with second-degree murder. The Oxford Center is located in the Detroit suburb of Troy.

Further details reveal that Peterson is 58 years old and Gary Marken is 65 years old. The U.S. Food and Drug Administration has cleared hyperbaric chambers to be marketed as safe and effective for 13 disorders, including severe burns, decompression sickness, and non-healing wounds. Additionally, Moffitt was charged with involuntary manslaughter and intentionally placing false medical information on a medical records chart.