Tamela Peterson, the CEO of the Oxford Center in Troy, ran away from detectives when they asked for her cellphone and had her son scrub her laptop days after 5-year-old Thomas Cooper was burned alive inside one of the center’s hyperbaric oxygen chambers on Jan. 31, Troy Police say.
Still, police found electronic messages on Peterson’s devices, said Detective Danielle Trigger, including an exchange in which Peterson sent photos of the boy’s burning body and wrote “something to the effect of: ‘If my leg was on fire, I would at least try to hit it and put it out. He just laid there and did nothing.’ ”
Peterson’s messages also show that when she was asked whether the company was promoting hyperbaric chambers to treat erectile dysfunction, she responded: “Whatever gets bodies in those chambers, lol,” according to a transcript of Trigger’s March 7 testimony before 52-4 District Court Magistrate Elizabeth Chiappelli, which was obtained by the Detroit Free Press.
The Oxford Center’s CEO and founder Tamela Peterson, 58, of Brighton, listens to attorneys speak as she is arraigned in front of Judge Elizabeth Chiappelli at the Oakland County 52-4 District Court in Troy on Tuesday, March 11, 2025, in 5-year-old child’s hyperbaric chamber death.
Peterson, 58, of Brighton, is charged with second-degree murder and involuntary manslaughter in Thomas’ death, as are the Oxford Center’s operations director, Gary Marken, 65, of Spring Arbor, and its safety and training director, Jeffrey Mosteller, 64, of Clinton Township.
A fourth person, Aleta Harward Moffitt, 60, of Rochester Hills, was the operator of the chamber on the morning of Thomas’ death and is charged with involuntary manslaughter and intentionally placing false information on a medical record.
Trigger told the judge her testimony “only begins to paint the picture of the blatant neglect for safety protocols on behalf of the Oxford Center that ultimately resulted in the loss of Cooper’s life,” according to the transcript.
“The investigation has shown a clear history of dishonesty, interference with investigations, predatory behavior towards vulnerable individuals desperately trying to get treatment, and a culture of negligence and unsafe practices that’s gone on for years.”
The Oxford Center, which has a second location in Brighton, offered hyperbaric oxygen therapy for a variety of conditions that are not approved by the U.S. Food and Drug Administration, including autism, cerebral palsy, cancer and autoimmune diseases.
Officials respond to an incident at the Oxford Center in Troy on Friday, Jan. 31, 2025.
Thomas was undergoing his 36th of 40 treatments, Trigger said, when he died. The Cooper family’s attorney told the Free Press he was being treated at the center for ADHD and sleep apnea, which also are not conditions approved for treatment with hyperbaric oxygen therapy.
Michigan Attorney General Dana Nessel described the business as “unscrupulous,” saying that, for years, Peterson, Marken and Mosteller disregarded safety measures. They used the highly pressurized oxygen chambers on children’s bodies “over and over again to provide unaccredited and debunked so-called treatments, chiefly because it brought cash into the door.”
But the testimony Trigger presented about the four accused in the death of the boy from Royal Oak paints a clearer picture of the state attorney general’s case against them.
Trigger testified that for years, Oxford Center staff “blatantly ignored” safety measures that could have kept Thomas alive, including a failure to use grounding straps, which typically are worn around the wrist during hyperbaric oxygen therapy to discharge static electricity that could spark a fire.
Former employees told police they’d been advised by Peterson, Marken and Mosteller that the straps weren’t necessary — even though industry experts, safety manuals, and the Oxford Center’s own training materials suggest otherwise, Trigger said. One former employee described as a certified hyperbaric technologist told the three she refused to run the hyperbaric chambers due to the lack of safety practices. She was fired, Trigger said.
Mosteller performed his own safety experiment in an attempt to prove grounding straps were not necessary, former employees said. Mosteller, in an interview, couldn’t tell police the name of a single medical facility in his 41 years of hyperbaric chamber experience that did not use them, Trigger said
Hyperbaric chambers contain 100% oxygen that is pressurized. Those conditions make the environment inside them highly combustible. Trigger said waivers signed by patients and the parents of children who were treated at the center didn’t include warnings of a fire hazard.
And while adults were required to wear medical scrubs when using the center’s chambers, children were allowed to wear their own pajamas inside, so long as they were made of 100% cotton, she said.
The type of material matters, according to a 1997 study that analyzed 73 years of data on hyperbaric chamber fires globally and their causes. It found synthetic materials and wool fibers can “build up static charges (and) should not be permitted inside the chamber” because of the risk that they could ignite a fire.
A video obtained by Troy police showed that the tags on Thomas’ pajamas were never checked to ensure they were made of cotton before he went inside the chamber, Trigger said.
Nessel said it was a single spark that led to the explosion that killed Thomas.
Trigger testified that the video shows the boy lying on a black mattress that had been covered by a white sheet. There was a pillow with a patterned pillowcase on it beneath his head. A gray blanket that had just been taken out of the dryer by Moffitt covered him. Trigger noted that the pillows used inside the chambers at the facility were 100 percent polyester, which is prohibited for use in hyperbaric chambers, “partially due to the fire risk.”
“He rolls onto his side and pulls his knee up towards his chest, which results in a visible ignition,” Trigger said. “The chamber immediately begins to burn internally and in what could only be described as a fireball, ultimately killing Thomas Cooper. At the time of the initial ignition to the time the inside of the chamber is fully engulfed in flames, killing Cooper, is approximately three seconds.”
Thomas Cooper, age 5, died at The Oxford Center in Troy after a hyperbaric chamber he was in exploded.
Trigger said the video did not show Thomas wearing a grounding strap. Detectives later found grounding straps in what she described as a “junk drawer.”
More, “I observed what appeared to be a grounding wire for the chamber involved in the incident … wrapped in electrical tape and was clearly in worse condition or inconsistent with the other chambers in the room,” Trigger said. “Investigators also learned that the other two chambers within the facility were only a few years old, while the chamber involved in the incident had a manufacturer date of 2013.”
Authorities also allege that Marken tampered with the life cycle indicator on the hyperbaric chamber that killed Thomas, dialing back the number of times it had been used.
Trigger testified that witnesses saw Marken use a screwdriver “to remove the panel from the side of the chamber, remove the cycle counter, and roll back the number in order to make the cycle count look lower and to extend the life of the chamber. …
“They were confident that this was likely done at the direction of Peterson,” Trigger said. Employees described Marken as Peterson’s “right hand” and the “muscle” of the operation, suggesting he and Peterson were “one and the same,” Trigger said.
The chamber that Thomas used on the day he died hadn’t undergone routine maintenance or inspection by the manufacturer, California-based Sechrist Industries, since 2022, Trigger said.
And when the company last inspected the machine in 2022, it documented that the chamber had been used more than 20,000 times, she testified. But when the device was checked after the fire, the life cycle count had been dialed back to 19,894.
Police recovered a November 2024 email exchange between Peterson and the chamber’s manufacturer that showed she had requested an inspection of all the hyperbaric chambers on-site, Trigger said.
The company declined to inspect the hyperbaric oxygen chamber that killed Thomas because of its high life cycle, and “Peterson then responds stating that they had sold that chamber and it was no longer in use,” Trigger testified.
Moffitt and two other hyperbaric chamber technicians were not certified to administer the treatments, Trigger said. Peterson and Marken had certifications that lapsed prior to 2020. Additionally, she said a physician hasn’t been present at the Oxford Center to oversee hyperbaric treatments for years.
On the morning of Thomas’ death, Peterson arrived at the Oxford Center with Mosteller and began yelling that the manufacturer needed to get there quickly “because they do everything by the book” at the center, Trigger said.
But Trigger alleged Peterson tried to hide video footage from detectives, first telling them recordings from the Troy facility were accessible only at the center’s Brighton location, and then later stating she did not remember the password to access the video system.
While the investigation remains ongoing, the Oxford Center’s Brighton location was still administering hyperbaric treatments, Trigger said.
All four defendants have pleaded not guilty and were being held in the Oakland County Jail with bonds set at $2 million for Peterson, $250,000 each for Marken and Mosteller, and $100,000 for Moffitt.
Probable cause conferences are set for Wednesday, with preliminary hearings set for March 26.
Peterson’s attorney, Gerald Gleeson II, said he wanted to obtain the investigation documents from the Attorney General before commenting on Trigger’s testimony.
When reached by email, Marken’s attorney, Raymond Cassar, did not immediately comment on the allegations.
An attorney for Mosteller was not listed in court records as of Wednesday afternoon.
Cassar previously said the tragedy was an accident rather than intentional. He said Marken wasn’t tasked with overseeing the hyperbaric chamber, and the charges against him were shocking to Marken and his family.
“We’re going to fight,” Cassar pledged.
Ellen Michaels, a lawyer representing Moffitt, said Moffitt was an hourly worker at the Oxford Center who adhered to corporate policies created by its leaders.
“Everything that has been presented to the court to this point are allegations, not facts, not evidence,” Michaels said. “We look forward to reviewing the actual evidence. We believe in letting this process unfold.”
Andrea Sahouri covers criminal justice for the Detroit Free Press. Contact her at asahouri@freepress.com or on X: @andreamsahouri.
This article originally appeared on Detroit Free Press: After boy died in hyperbaric chamber, police say CEO scrubbed evidence
