Jeffrey Mosteller, the safety director at the Oxford Center in Troy, is scheduled to be sentenced Monday, Aug. 31, at 8:30 a.m., to a term of 19 months to 15 years in prison under a plea deal in the hyperbaric chamber explosion that killed 5-year-old Thomas Cooper of Novi.
Oakland County Circuit Judge Kwame Rowe is expected to impose the sentence, which reflects the terms of a plea deal Mosteller struck with prosecutors in July.
Mosteller pleaded no contest to involuntary manslaughter on July 21 after a second-degree homicide charge was dismissed as part of the agreement. A no-contest plea is not an admission of guilt but is treated as one for sentencing purposes.
Thomas died Jan. 31, 2025, when a hyperbaric chamber at the Oxford Center caught fire and exploded while he was receiving treatment. Prosecutors said the center had banned the use of wrist grounding straps during hyperbaric oxygen therapy, arguing a strap would have dissipated static electricity and prevented the fire.
Mosteller was accused of deliberately disregarding safety protocols published by the National Fire Protection Association and Sechrist, the chamber's manufacturer.
As we reported July 24, Mosteller's plea deal set the sentencing range Judge Rowe will consider at the Aug. 31 hearing.
Michigan Attorney General Dana Nessel, whose office brought the charges against all four defendants, said in a news release at the time of the July 21 plea that Mosteller allowed an outdated device to operate in defiance of safety standards and called Thomas's death a completely preventable tragedy.
Three co-defendants still face charges
Three other Oxford Center employees remain charged in Thomas's death:
- Tamela Peterson, the center's owner and founder, faces second-degree homicide and involuntary manslaughter.
- Gary Marken, a management assistant, faces second-degree homicide and involuntary manslaughter.
- Aleta Moffitt, who was reportedly operating the chamber when the explosion occurred, is charged with involuntary manslaughter and placing false information on a chart.
Judge Rowe denied Peterson's motion to quash the murder charge on July 23, ruling prosecutors need only prove she acted in obvious disregard of life-endangering consequences. Peterson's attorney Gerald Gleeson said July 24 that Peterson would appeal, according to The Oakland Press. Rowe has stayed proceedings in Peterson's case pending that appeal.
No next court date has been confirmed for Marken or Moffitt. All four defendants are also named in a civil lawsuit stemming from Thomas's death.
