November 14, 2026, 12:01 a.m. ET
WASHINGTON — Matt Lambert’s problems began more than two years ago, when he claimed in court that his $1 million Washington, D.C., penthouse had become unlivable.
For more than a year, mold grew along her walls, water saturated the ceiling and fire suppression system pipes leaked, Lambert alleged in a March 2025 lawsuit against her homeowners association.
The dispute escalated into a costly, years-long legal battle over who, if anyone, was responsible for the damages.
Police now believe those issues likely motivated Lambert to kill his building manager, James Stuart, and injure five other people in an early morning shooting on Nov. 12, which also led to his suicide. One of the victims remains in critical condition, while the other three do not have life-threatening injuries, police said.
Evidence suggests Lambert “planned” the attack, Washington Police Chief Jeffery Carroll said.
Cameras inside the VIDA Fitness gym show Lambert waited more than an hour for Stuart to arrive, before approaching and shooting him from behind. Then he ran back to his unit, barricaded himself, started shooting a rifle from a balcony, cut a natural gas line to his chimney and started a fire.
“We found several hundred rounds of ammunition there,” Carroll said, adding that they also found the broken gas line and fire accelerants.
Social media posts in the months and days leading up to the shooting appeared to show Lambert’s growing frustration with his condo issues and the management of his building.
At 8:06 a.m. on November 12, an X account associated with Lambert said, “My manifesto is an engineering report” and attached screenshots of issues with his Metropole Condominium.
Hours earlier, around 4:30 a.m., he posted screenshots of an email Metropole had sent to residents alerting them that an air duct sensor had been triggered. The email explained that the building’s fire alarm had thus been deactivated.
Joel Braithwaite, Lambert’s attorney, said the doctor has spent more than $300,000 on legal fees and upkeep of the home since the water and mold problems began in 2024. Braithwaite said Lambert felt he had been treated differently from other tenants and that his problems had not been addressed by management.
In Lambert’s long legal battle
Lambert purchased the two-bedroom penthouse in the trendy Logan Circle neighborhood for $1,095,000 in 2016, according to property records. For at least seven years, he seemed to live in his two-story house without any problems.
The problems, he says in the suit, began after the Metropole Condominium Association began work on the condo’s facade to remediate the building envelope in 2023. The repairs cost Lambert about $15,000, according to court documents. During construction, the homeowners association asked residents to report any water intrusion, according to the suit.
A year later, in March 2024, Lambert began noticing water flooding his unit. And in the fall of that year, excess moisture began to build up behind the drywall and mold was visible, according to the lawsuit. The mold, he claimed, was “detectable by smell” and his electric curtains no longer worked.
The building denied the presence of mold and Lambert hired independent contractors to assess the property, the lawsuit states. When those investigations revealed “visible mold contamination,” he asked the HOA to begin mold remediation, remove the drywall, and reimburse his independent contractors’ costs.
“These intrusions have been reported to James Stuart of EJF since March,” Lambert wrote in an October 2024 email, according to the lawsuit.
By the time Lambert filed suit less than six months later, in March 2025, he had “deconstructed” his condo down to the metal frames, which showed “signs of water intrusion and high humidity in the unit,” according to court documents.
In its July 2024 response, the Metropole condominium association denied that the facade project was the cause of the problems, citing the year between the project’s completion and when Lambert’s water and mold problems appear to have begun.
In October 2025, Metropole filed a lawsuit against Urban Adventure Companies, the group that owns VIDA Fitness, and the owners of VIDA’s retail space.
“The high humidity levels identified in Unit 704, owned by Plaintiff Lambert, are more than likely caused by the use of the dryers and a failure of the dryer exhaust system that exclusively serves Unit C9,” the HOA argued in the third-party lawsuit.
Stuart, the Metropole building manager, was a witness in the trial.
The trial was underway when Lambert killed Stuart on November 12.
An attorney for the retail space owners declined USA TODAY’s request for comment. Attorneys for the condo association and VIDA Fitness could not immediately be reached.
Braithwaite, Lambert’s attorney, said at a Nov. 12 news conference that the discovery process in lawsuits can “have adverse consequences” on clients. The pending motions and depositions, which Lambert has recently been involved in, he said, could be exhausting.
“When a matter is litigated, there is never a need to resolve these issues through violence,” Braithwaite said. “Ultimately, these issues should have been resolved in court.”
Was Lambert’s health affected by the mold?
For more than a year before the shooting, Lambert had not primarily lived in his mold-infested condominium, his lawyer said. It is unclear whether Lambert remained in the unit the night before the shooting.
Earlier that week, he spoke on a panel on artificial intelligence at a health care conference in Orlando. The panel took place on Tuesday, November 11, two days before filming.
Black mold is a fungus that grows in warm, humid areas — like basements, showers and windows as well as naturally in the environment — and can cause a human immune system reaction, especially if a person is susceptible to it, according to the Cleveland Clinic.
“Exposure to black mold is more strongly associated with respiratory problems, such as asthma, nasal congestion, wheezing and coughing,” said Dr. Brintha Vasagar, a family physician and chief medical officer at Progressive Community Health Centers in Milwaukee.
Other symptoms may include itchy eyes or throat, runny nose, sneezing, and chest tightness or difficulty breathing, adds the Cleveland Clinic.
Despite misconceptions, “black mold is no more dangerous than any other type of mold,” the clinic noted. “All types of fungi can affect you if you have mold allergies.”
Vasagar added that there is “no data indicating that mold causes changes in mental health,” but adds that “humid conditions and mold have both been linked to feelings of depression and anxiety.”
“This may be due to increased stress or poorer sleep rather than a direct impact of the mold,” she explained.
Gn headline
