TROY, Mich. – We’ve learned much more about the specific allegations against the CEO and three other employees of an Oakland County health care facility where a 5-year-old boy was killed in a hyperbaric chamber explosion.
The explosion happened Jan. 31, 2025, at the Oxford Center in Troy. Five-year-old Thomas Cooper was receiving treatment inside the hyperbaric chamber when it exploded, killing him and injuring his mother.
4 people facing charges
Oxford Center founder and CEO Tamela Peterson, 58, of Brighton, is charged with second-degree murder and an alternative count of involuntary manslaughter, which means a jury can decide which charge applies to her conduct.
Safety manager Jeffrey Mosteller, 64, of Clinton Township, and primary management assistant Gary Marken, 65, of Spring Arbor, are both facing the same charges as Peterson.
Aleta Moffitt, 60, of Rochester Hills, is charged with involuntary manslaughter and falsifying medical records. Prosecutors said she was operating the hyperbaric chamber at the time of the explosion.
Swear-to outlines allegations
Local 4 has obtained a transcript of the swear-to in this case, which took place March 7 before Magistrate Elizabeth Chiappelli at 52-4 District Court in Troy.
During the swear-to, Detective Danielle Trigger, of the Troy Police Department, laid out the allegations against Peterson, Marken, Mosteller, and Moffitt.
WARNING: Some of the details included in this article are disturbing and graphic in nature.
Scene at Oxford Center after explosion
Trigger said the explosion happened at 7:54 a.m. Jan. 31, 2025, at the Oxford Center, which is at 165 Kirts Boulevard in Troy.
Troy police were sent to the facility for a report of a hyperbaric chamber exploding with a child trapped inside.
“Officers arrived on scene and located a 5-year-old boy ... obviously deceased and burned beyond recognition inside of the middle chamber of three chambers that were located inside of the room,” Trigger said.
She said two employees and another patient who had been receiving hyperbaric treatment were at the facility. Those two employees were Moffitt and a front-desk employee.
Cooper’s mother was there, and she had burns on her arms and hands, “as a result of trying to remove her son from the burning chamber,” the swear-to reads.
Peterson arrives
Police said Peterson and Mosteller arrived while officers were moving everyone to another suite for interviews.
“Peterson began yelling inside of the lobby of the adjoining suite about how the manufacturer needed to get to the scene immediately to find out what happened because they do everything by the book at her center,” Trigger said.
Surveillance footage availability
Investigators said they were told they would have to go to the Oxford Center’s Brighton branch to view the business' full surveillance footage of what happened.
A short clip of one specific view of the chamber was provided to investigators at the scene, Trigger said. (The details of that video are outlined in the below section. WARNING: They are disturbing.)
Trigger said investigators later learned that they could have gotten the full surveillance footage at the Troy branch, “but they were not afforded that opportunity by the staff on the date of the incident.”
Video shows fire starting
The footage provided at the Troy scene showed Cooper inside the chamber with a gray blanket and a pillow, police said.
“Cooper is moving around within the chamber, moving the blanket and sheet around with him,” Trigger said. “He rolls onto his side and pulls his knee up toward his chest, which results in a visible ignition.
“The chamber immediately begins to burn internally and, in what could only be described as a fireball, ultimately killing Cooper.”
Trigger said the total time between the ignition and the chamber becoming fully engulfed in flames was about three seconds.
Clothing inside chamber
Police said adults who entered hyperbaric chambers at the facility had to change into scrubs that were provided by the Oxford Center.
But children were allowed to wear their own pajamas, as long as those pajamas were 100% cotton, the swear-to reads.
Treatment plan
Investigators said Cooper was supposed to receive 40 rounds of hyperbaric chamber treatment, and Jan. 31, 2025, was his 36th round of treatment.
Records at Troy branch
Mosteller let investigators make copies of maintenance and service records for the hyperbaric chambers, including a user’s manual, Trigger said.
“Detective Barrett and I were reviewing the manual and observed a page that depicted a wrist strap that was meant to be applied to a patient’s wrist while they were receiving treatment and inside of the chamber in order to ground them,” Trigger said.
She said they rewatched the surveillance footage and could tell that Cooper did not have a grounding wrist strap at the time of the explosion.
Oxford Center’s history
The Michigan Attorney General’s Office reached out to Troy police and told them about a multi-year investigation into the Oxford Center.
That investigation was for “assorted fraud offenses, including unauthorized practice of a health profession,” the swear-to says.
“Conversations with investigators at the attorney general’s office made Troy investigators aware that the CEO of the company, Tamela Peterson, along with her IT personnel, had a history of tampering with and/or destroying evidence, specifically CCTV footage and records related to the investigation that the AG’s office had previously been conducting.”
Grounding wire
Trigger said she reviewed photos of the scene and noticed that the grounding wire for the chamber that exploded was “wrapped in electrical tape and was clearly in worse condition or inconsistent with the other chambers in the room.”
Representatives from Sechrist, the company that manufactured the hyperbaric chamber, viewed the picture and told police that they would have never repaired a grounding wire in that way, Trigger said.
“They further advised that had a wire been repaired by an outside electrician, they would have had to tag out the chamber as being unusable,” Trigger said. “(Sechrist) would then have had to return to the location to inspect the work in the chamber before it could be used again. That did not occur.”
Chamber was 11+ years old
Investigators said the other two hyperbaric chambers in the room were only a few years old, but the one that exploded had a manufacturer date of 2013.
Lack of grounding wrist strap use
Police spoke to the other patient who had been receiving hyperbaric chamber treatment at the time of the explosion.
She told officers that she had received “well over 40″ hyperbaric treatments at the Oxford Center in Troy and had never had a grounding wrist strap attached during any of those treatments.
“Multiple tips came in from previous patients and previous employees of the Oxford Center,” Trigger said. “Everyone interviewed, some of which had received or administered hundreds of treatments, all indicated that a grounding wrist strap had never been utilized.”
Previous employees told police that they had specifically expressed concerns to Peterson, Mosteller, and Marken about the center’s trend of not using the grounding wrist straps on patients “and the lack of checking grounding on the chambers,” according to the swear-to.
“All of the employees were advised that none of these measures were necessary,” Trigger said. “One of the employees was an individual who was a certified hyperbaric technologist and who had been working in the field extensively for many years. She advised Peterson, Mosteller, and Marken that due to their lack of safety practices she would no longer assist with administering hyperbaric treatments. As a result, she was fired from the company.”
Marken and Mosteller: What they did at Oxford Center
Police said Marken was described to them as Peterson’s “right hand” and “muscle” within the company.
Marken and Peterson were described as “one and the same,” Trigger said, quoting former employees.
“While Mosteller was described as being responsible for overseeing safety at all of the facilities, Marken was described as being a primary hyperbaric technician who would oversee much of the hands-on (hyperbaric oxygen therapy) training early on and then transitioned into working more closely with Peterson in an administrative role where, we were advised, he would sit in on interviews and terminations, as well as mostly sharing an office with Peterson once they moved to the Brighton location,” Trigger said.
Chamber cycle count rolled back?
Police reached out to Sechrist and requested all records linked to the chamber that had exploded.
Sechrist workers said they hadn’t performed routine maintenance on the hyperbaric chambers at the Oxford Center in Troy since 2022.
“They further advised that they had written documentation between themselves and Peterson advising her that the cycle count on the chamber that had exploded was over 20,000 cycles when they were at the facility in 2022,” Trigger said. “I reviewed photos of the chamber cycle counter from the date of the incident that were taken on scene, which showed that the chamber cycle count on that date was 19,894, which would be consistent with the rollbacks reported by ex-employees.”
Emails between manufacturer and Peterson
Sechrist provided police with an email exchange with Peterson from Nov. 11, 2024, to Nov. 13, 2024.
“In this exchange of emails, Peterson contacts the manufacturer and asks them to come to perform service on all of the chambers at her two facilities,” Trigger said. “Sechrist states that they are unable to perform service on the chamber that exploded because it was over 20,000 cycles the last time they were there.”
Peterson asked Sechrist for proof that the cycle count was over 20,000, so the manufacturer sent a report from the 2022 maintenance.
“Peterson then responds stating that they had sold that chamber and it was no longer in use,” Trigger said.
Hyperbaric chamber experts offer opinions
Police said they brought in two experts with decades of experience in hyperbaric oxygen treatments, medical training, engineering experience, and fire safety experience to review the case.
Those experts were allowed to watch the surveillance footage and investigate the facility.
“They both provided individual reports of their findings, which ultimately indicated that a large number of required safety protocols had been completely disregarded by the Oxford Center on the date of Thomas Cooper’s death,” Trigger said.
The experts told police that, in their opinion, Cooper would still be alive if he had been wearing the grounding wrist strap.
The experts also said the Oxford Center failed to perform a “safety pause” before Cooper entered the chamber. The safety pause is designed to make sure the patient’s clothing is 100% cotton and that they aren’t wearing any lotions or medical patches.
“They advised us of daily checks that are supposed to take place prior to putting somebody in a chamber for treatment,” Trigger said. “This did not occur at the Oxford Center.”
Police said footage showed that nobody checked the tags on Cooper’s clothing. Nobody checked him for bandages, lotions, or any other products, Trigger said.
Experts also told police that a physician must be present for hyperbaric treatments, and that was not the case on the day of the explosion.
“Later interviews confirm that a physician was never present overseeing treatments at the Troy facility for the past several years,” Trigger said.
Blanket straight out of dryer
Police said the blanket that Cooper had with him inside the chamber came straight from a dryer.
“On the video, Aleta Moffitt can be observed removing a blanket directly from the running dryer and handing it to Cooper to take into the chamber with him for the treatment,” Trigger said.
Certifications
Police checked with the Michigan Department of Licensing and Regulatory Affairs to see whether employees at the Oxford Center were certified to give hyperbaric treatments.
Moffitt was one of three employees (the other two are not charged in this case) who had never been certified to administer hyperbaric treatments, Trigger said. Peterson and Marken had previously been certified, but their certifications lapsed before 2020.
Mosteller had a current certification to administer hyperbaric treatments at the time of the explosion, police said.
None of these employees were registered nurses or physicians.
Mosteller interviewed about grounding
Mosteller told detectives during an interview that he had taught Marken and Peterson many years ago at Detroit Receiving Hospital, which is where they received their hyperbaric certifications.
“Mosteller advised that during that time, he would have explicitly instructed them to use grounding wrist straps and check chamber grounding regularly,” Trigger said. “Mosteller advised he came to work at the Oxford Center around 2019, and when he arrived, they were not utilizing that training related to grounding.”
He told officials that when he questioned the lack of training on grounding, Peterson told him that the straps weren’t necessary, according to the swear-to.
Mosteller’s testing
Mosteller told police that he performed his own testing to “convince himself to agree with” the theory that grounding straps weren’t necessary, Trigger said.
He said he would “occasionally” check the chamber grounding, but not regularly, the swear-to says.
He also admitted that while he administered several of Cooper’s treatments, he never checked the boy’s clothing tags or asked the parents questions about what might be on him, Trigger said.
Grounding policy
Mosteller told officials that Peterson and Marken made the initial decision to discontinue the use of grounding wrist straps, according to authorities.
“But he agreed with their decision and implemented it internally moving forward despite coauthoring multiple training materials with Peterson, copy-written under the Oxford Center name, that indicated the importance of the grounding wrist strap and checking chamber grounding,” Trigger said.
Polyester pillows
When the experts visited the Oxford Center (this was after the explosion), they noticed that the pillows being used in the hyperbaric chambers were filled with 100% polyester, according to police.
“100% polyester (is) an item that is listed as not being allowed inside of the chambers, partially due to the fire risk,” Trigger said.
Trigger said the manufacturer offers hyperbaric-safe pillows for an added cost.
“Experts also took notice that the disclosure forms and waivers signed by patients or their parents specifically did not include the risks of fire or death,” she said.
What investigators found in junk drawer
Investigators said they found grounding wrist straps and a multimeter in “a drawer that could really only be described as a junk drawer” in the laundry room area.
“The wrist straps were at the back of that drawer, and the cords were clearly oxidized as though they had not been used or moved and had just been sitting for an extended period of time,” Trigger said.
The multimeter was still in the bag with the caps on both ends of the cords, and the cords appeared to have never been unraveled, she said. Police don’t believe it had ever been used to test grounding.
Incorrect logs
Police reviewed the logs of Cooper’s treatment on Jan. 31, which listed him as “leaving the bottom,” or coming back to the surface from being pressurized, at 8:08 a.m. and returning to the surface at 8:18 a.m.
“Both of those times were impossible, seeing as the fire had already occurred and he was deceased before 8 a.m.,” Trigger said.
When police received a list of internally recorded timestamps from Peterson’s attorney, they said they found nine inconsistencies between those times and the handwritten logs found at the scene.
Checklist changed
Investigators said they found daily and weekly checklists provided by the manufacturer that listed actions that were supposed to be performed on the hyperbaric chambers.
In 2019, the Oxford Center changed the form and removed any items relating to checking chamber grounding or patient grounding, according to Trigger.
Peterson ‘ran from investigators’ who tried to take her phone
Trigger said Peterson tried to run away from investigators who went to the Brighton branch of the Oxford Center to take her cellphone.
“Upon approaching Peterson and advising her that we would be taking her cellular device, she ran from investigators,” Trigger said. “They were ultimately able to get to her and retrieve her device.”
Police say Peterson had son wipe laptop
When they “got to” Peterson to take her phone, investigators said Trigger admitted to having her laptop wiped.
“Peterson openly admitted to investigators that she’d had her son wipe her laptop completely within days of the incident,” Trigger said.
Peterson claims to forget password
Investigators said when they tried to retrieve surveillance video footage from all of Cooper’s treatments, Peterson told them that she didn’t remember her password to access the system.
IT workers told police that Peterson should have known her password because “they had just given it to her very recently.”
The IT workers ultimately gave police the login information to access the video.
Text message, photos about boy’s death
When police reviewed Peterson’s cellphone and laptop, they said they found that she had taken still photos of Cooper from the surveillance video.
Those still photos showed Cooper burning inside the hyperbaric chamber, Trigger said.
“In the message exchange along with those photos, (Peterson) stated 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,’” Trigger said.
‘Whatever gets bodies in those chambers’
Trigger said investigators discovered messages from people asking Peterson whether the Oxford Center promoted hyperbaric treatments for erectile dysfunction.
Peterson responded, “Whatever gets bodies in those chambers, lol,” according to authorities.
Peterson ‘unbelievably involved’
Messages and emails showed that Peterson was “constantly monitoring video in real time at the Troy facility,” the swear-to reads.
“The content of the correspondence made it abundantly clear that she was unbelievably involved in the oversight of the day-to-day operations of the facility in Troy,” Trigger said.
Reason for visa to China, Iraqi currency
Trigger included some background information about Peterson during the swear-to, including that her husband is a forensic accountant and they deal with an almost exclusively cash business.
In the end of the December, Peterson acquired a 90-day visa to travel to China because of connections to her daughter-in-law, police said.
“Emails were discovered indicating that she had been purchasing uncirculated Iraqi currency, and her son-in-law appeared to have ties to the Middle East,” Trigger said.
Destruction of evidence, witness intimidation
During the previous investigation by the Michigan Attorney General into the Oxford Center, there were claims of destruction of evidence and witness intimidation, Trigger said.
“Many of the individuals who did come forward to provide information, ex-employees, specifically, cited concerns about retribution from Peterson,” the swear-to reads. “These individuals referenced Peterson having a history of calling licensing boards to make claims to get licenses revoked from people cooperating against her and making veiled threats to individuals planning to leave the company.”
Oxford Center preying on desperation
In its conclusion, the swear-to says the information covered in the first 20 pages “only begins to paint the picture” of the Oxford Center’s neglect for safety.
Investigators said they found 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.”
Oxford Center in Brighton
Trigger said the Brighton branch of the Oxford Center has eight hyperbaric oxygen chambers. The Troy branch had three.
“On multiple occasions when investigators have been to the Brighton facility since this incident having occurred, they’ve observed a significant number of patients at the facility to receive some form of treatment,” Trigger said.
The swear-to ended at 9:41 a.m. March 7, 2025.
