A longtime physician and healthcare technology executive allegedly opened fire inside his Washington, DC, apartment building during a bitter dispute over water damage and mold in his $1 million home.
Dr. Matt Lambert, 55, shot and killed the building manager inside the tower’s gym, wounded several other people and later died from a self-inflicted gunshot wound.
A close relative of Lambert declined to comment when contacted by the Daily Mail about the shooting.
Lambert had been engaged in a prolonged legal fight with the Metropole Condominium Association, which manages the luxury building on 15th Street near Logan Circle.
In court filings and a series of detailed posts on X, formerly known as Twitter, he accused the association of causing water intrusion and mold during renovation work on the building’s facade.
The frustrated doctor eventually barricaded himself inside his one-bedroom apartment, built in 2008 and valued at slightly more than $1 million, before taking his own life.
At 8.06am, while he was believed to be inside the apartment, Lambert posted his final message: ‘My manifesto is an engineering report.’
He included a screenshot from a CED Technologies report that appeared to support his allegations, along with what seemed to be a log of complaints about problems inside the building.
Dr Matt Lambert, 55, allegedly killed the building manager inside a Washington, DC, gym, injured several others and later died from a self-inflicted gunshot wound
The Washington, DC, gunman died after an hour-long standoff with police, having barricaded himself inside an apartment after a deadly gym shooting
In another disturbing post, Lambert appeared to foreshadow the violence on April 28 while responding to a resident’s complaint that the building’s hot water was not working.
‘If you’re looking for the building manager, I would check the gym,’ he wrote.
The day before the shooting, Lambert claimed the dispute had left him without a shower, dryer, heating and cooling system or cooking facilities for six months.
Authorities said the suspect had been involved in a dispute with his homeowners association before the attack.
‘We do know there was a conflict between him and the homeowners association of that building, but at this point we’re continuing to look into that,’ Metropolitan Police Chief Jeffery Carroll said during a press conference.
A male victim died after being shot in the back inside VIDA Fitness in Logan Circle. Police said the suspect was believed to be a member of the gym.
Police said at least one injured person was in critical condition, while three others suffered injuries that were not considered life-threatening. The update came shortly before the gunman shot himself.
Officers located Lambert barricaded inside an apartment on 15th Street. Negotiators spoke with him for approximately an hour before police heard a gunshot.
Police then forced their way into the building after the man reportedly fired twice through the door in their direction.
Inside, officers found Lambert suffering from a self-inflicted gunshot wound. A search of the apartment later uncovered three firearms.
The interior of Lambert’s apartment in November 2024, showing damage caused by water intrusion
Lambert shared this November 2024 photograph of remedial work inside his apartment one day before the shooting
Lambert’s final post declared: ‘My manifesto is an engineering report.’ He attached an excerpt from a CED Technologies report that appeared to support his claims
He also shared what appeared to be a record of reported problems inside the building
In March, Lambert was appointed chief medical officer and head of product strategy at Advantmed, a company specializing in healthcare information management and risk adjustment.
His role was expected to focus on the company’s in-home assessment program.
‘In-home assessments provide a meaningful opportunity to engage members while strengthening risk and quality performance,’ Lambert said after taking the position.
He earned his medical degree from Marshall University and trained in emergency medicine before moving into a series of chief medical officer roles in the private sector.
Lambert also served as chief medical information officer for New York City Health and Hospitals.
Beginning in October 2025, he documented his dispute with the Metropole in hundreds of online posts featuring photographs, records and complaints.
His grievances extended beyond the alleged water damage in his apartment, encompassing a wide range of concerns about the building and its management.
A lawsuit he filed in March 2025 alleged that facade work launched by Metropole in March 2023 had caused ‘suspected water intrusion, mold, significant moisture accumulation, and/or related damage.’
Lambert maintained that his apartment had experienced ‘no significant water intrusion, mold, moldy smells, moisture accumulation, or related damage’ before the renovation began.
Investigators cut openings into Lambert’s ceiling while examining reports of mold and water damage
Black mold reportedly found inside Lambert’s apartment
As a condominium owner, Lambert paid Metropole $15,357 toward the facade project. He said he first noticed damage in March 2024.
He reported the first incident of ‘water intrusion’ after the association had actively asked residents to report such problems during the construction work.
According to the lawsuit, Metropole did not cut into the drywall to investigate whether water was trapped behind the wall until August 2024.
By the following month, the electric blind beneath the opening had stopped working, while foul-smelling mold began spreading around the area.
Lambert alleged that Metropole denied mold was present and attempted to close the opening rather than address his complaints.
He said two independent inspections found that significant moisture continued to collect in several parts of the apartment, including the concrete ceiling, soffit, baseboards, windowsills and exterior walls.
Lambert formally asked the association to complete repairs recommended by the inspectors and reimburse him for the expenses he had incurred.
The lawsuit alleged that Metropole failed to fulfill those demands despite receiving extensive photographic evidence.
‘[Metropole’s] work caused a moisture saturated ceiling, mold-covered external walls, and moisture-saturated floorboards under the windows, corrosion of metal surfaces under the drywall,’ the lawsuit claimed.
On October 21, 2024, Metropole wrote to Lambert promising to cooperate on a solution. He later alleged that the promised action never materialized.
By November 11, Lambert said he had lost patience and hired a contractor to remove walls and flooring he described as saturated with moisture and badly damaged.
He claimed the work exposed additional black mold and leaking pipes that were worsening the condition of the apartment.
The lawsuit alleged that Metropole repeatedly promised to correct the damage but had not done so by the time the case was filed.
‘[Lambert’s] unit remains deconstructed torn down to the metal frame which bears signs of the water intrusion and elevated moisture in the unit,’ the filing stated.
Lambert moved out once the demolition began and said he could not return because rebuilding the apartment would risk further mold growth unless the underlying problems were resolved.
A bullet hole was visible in a window at the apartment complex
A man died after being shot inside VIDA Fitness in Logan Circle. Police said the suspect was believed to be a member of the gym
Witnesses described scenes of terror as the building manager was shot and other people were wounded, sending gym members and nearby residents scrambling for safety.
One gymgoer called the scene ‘horrific’ and said people could not leave without passing through the area where the gunman was located.
She said a man close to her was shot while she was walking on a treadmill.
Max Smith told NBC Washington that he left his apartment after a fire alarm sounded. Once outside, however, residents began hearing gunshots.
‘Everyone starts sprinting,’ he told the broadcaster.
Smith said he heard at least three or four shots and that at least 10 people took shelter inside the bathroom of Call Your Mother deli.
‘I’m very shaken up, you don’t expect it,’ he said.
More to come.