Doctor murdered building manager at luxury DC apartment complex then shot himself dead after yearslong meltdown over mold and mice inside his $1m home

A veteran doctor and medical tech boss went on a shooting rampage in his apartment building amid a bitter legal battle over water damage to his $1 million home.

Dr Matt Lambert, 55, shot dead the building manager James Stuart, 46, in the gym of the tower in Washington DC and wounded four others before killing himself.

A close relative of Lambert refused to comment when the Daily Mail called asking about the doctor in connection with the shooting.

Lambert had a long-running feud with Metropole Condominium Association, which operates the luxury residential tower on 15th Street near Logan Circle.

He claimed in a lawsuit, and in great detail on his Twitter account, that Metropole and its building contractors, EJF Real Estate Services, caused $290,000 in water damage and resulting mold during facade renovations.

The disgruntled doctor barricaded himself inside the seventh-floor one-bedroom unit, which was built in 2008 and worth just over $1 million, before killing himself.

Lambert's last post, at 8.06am while he was believed to be holed up inside his apartment, read: 'My manifesto is an engineering report.'

Attached was a screenshot of part of a report by CED Technologies that agreed with his claims, and what appeared to be a record of reported building issues.

Dr Matt Lambert, 55, shot dead the building manager in the gym of the building in Washington DC and wounded three others before turning the gun on himself

A Washington, DC, gunman killed himself after an hour-long standoff with police. He barricaded himself in an apartment after killing a man at a nearby gym and injuring four others 

Another chilling post by Lambert predicted his shocking crime on April 28 in response to a complaint by another resident about the hot water not working.

'If you're looking for the building manager, I would check the gym,' he wrote. 

Lambert in a post the day before the shooting claimed the saga left him with 'no shower, dryer, HVAC, and cooking' for six months.

Officials earlier said the suspect had a conflict with his HOA before the shooting. 

'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 at a press conference.

Stuart died after being shot in the back inside VIDA Fitness, which is inside the apartment building. Lambert then retreated upstairs to his apartment.

While inside, he set of the sprinkler system; started a fire; and complained on the phone to a neighbor, another property manager, and police negotiators about his feud with the building.

He also wounded four random people on the ground whom he fired on from his balcony, before eventually turning the gun on himself.

At least one of the injured is in critical condition, while three others suffered non-life-threatening injuries, police said.

When police approached Lambert's unit, he shot at them twice through the door but none of the officers were hit. 

The inside of Lamber's apartment in November 2024, the day he left the apartment and the walls and floors were ripped out to investigate the water damage and mold

The dismantling of the walls in Lambert's apartment in a photo from November 2024 that he posted a day before the shooting

Negotiators then spoke to him on the phone for an hour in an attempt to get him to surrender.

'While our negotiators were communicating with the suspect, they did hear a single gunshot. At which time, the suspect stopped talking to the officers,' Carroll said.

When police were eventually able to get inside, they found Lambert with a self-inflicted gunshot wound. 

Three guns - a pistol, shotgun, and rifle - were soon discovered during a search of the unit. Police said none of them were registered to Lambert.

Stuart was shot with the pistol, the four wounded picked off with the rifle, and the shotgun fired through the door at police.

Lambert was in March appointed chief medical officer and head of product strategy at Advantmed, a healthcare information management and risk adjustment company.

His focus was to be 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 at the time.

Lambert got his medical degree from Marshall University and trained in emergency medicine before a series of private sector chief medical officer jobs.

He was also the chief medical information officer for New York City Health and Hospitals.

Lambert's last post read: 'My manifesto is an engineering report.' Attached was a screenshot of part of a report by CED Technologies that agreed with his claims

He also attached what appeared to be a record of reported building issues

Lambert began documenting his feud with Metropole in October 2025, posting hundreds of photos, documents, and complaints. 

His complaints were not confined to his apartment and the disputed over the water damage, but to anything wrong with the building and its operations.

Lambert's lawsuit, filed in March 2025, claimed 'suspected water intrusion, mold, significant moisture accumulation, and/or related damage' was a direct result of facade work Metropole began in March 2023.

He claimed that before the work began, his apartment had 'no significant water intrusion, mold, moldy smells, moisture accumulation, or related damage'.

Metropole EJF Real Estate Services both denied causing the damage, claiming it was the fault of third parties beyond their control, and that Lambert should have done more to prevent it himself.

Lambert, as a condo owner, paid Metropole $15,357 as his contribution to the facade work until he began to notice the damage in March 2024, the lawsuit claimed.

He reported the first 'water intrusion' into his apartment, as Metropole had 'actively solicited' from residents when the work started.

It wasn't until August 2024 that Metropole cut a whole in Lambert's drywall to check if there was water running behind the wall.

By the next month, the electric blind under the hole in the drywall had stopped working and a stinking mold grew in the area.

However, the lawsuit claimed Metropole denied there was any mold and sought to close the hole and ignore Lambert's complaints.

Another chilling post by Lambert predicted his shocking crime on April 28 in response to a complaint by another resident about the hot water not working. 'If you're looking for the building manager, I would check the gym,' he wrote.

The condition of Lambert's apartment earlier this year, which he described as 'unliveable'

Lambert claimed that two independent assessments 'confirmed that substantial moisture continues to accumulate in key areas of the unit, including the cement ceiling, soffit, baseboards, windowsills, and exterior walls'.

He sent a formal request to Metropole to fix the damage in line with recommendations by the assessors, and reimburse him for all costs.

The lawsuit claimed Metropole failed to carry out any of his requests, despite him providing ample 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.

Metropole wrote to Lambert on October 21, 2024, promising to work with him to resolve the issues, but he claimed this never happened.

By November 11, he gave up and hired a contractor to remove the 'moisture saturated' walls and rotted floors.

He claimed this uncovered even more black mold and leaking pipes that were adding to the problem.

A photo Lambert posted to his Twitter to complain about the slow progress of the facade work

Another photo of the facade work from earlier this year. Lambert claimed the construction caused the water damage to his apartment

The lawsuit claimed Metropole made many promises to fix the problems, but had failed to deliver by the time the lawsuit 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,' it claimed.

He left the unit when the deconstruction began and claimed he wasn't able to return as putting the unit back together would just cause more mold to grow unless Metropole fixed the underlying problems.

The case dragged on for the next year and a half, and Lambert began documenting every problem with the building he could find, along with the slow progress of the facade work. 

Photos he posted included mold, corroded metal, cockroaches and other vermin, water running inside his walls, and notifications from building management about various utility interruptions.

He also complained he was being 'discriminated' against as work was done on other units the fix similar problems, but not his own.

Black mold that accumulated in Lambert's apartment

Photo of water damage elsewhere in the apartment building that Lambert posted to his Twitter

Holes cut into a ceiling in a public area of the apartment complex

Then on October 1 this year he posted an update on the case.

'After months of 'Luigi' tactics (delay, deny, defend) by the HOA, we were finally able to submit an independent engineering report into the record,' he wrote, referring to the Luigi Mangione murder case.

'The report addresses 704, the facade rehabilitation more broadly, and lists other units affected. When the time is right, I will share the report on X, with other Metropole owners, and with Logan Circle realtors.'

The report was only made public when Lambert posted it moments after he gunned down Stewart and barricaded himself in his 'uninhabitable' unit.

Lambert's rampage was two years and one day after he moved out of his unit so the contractors could dismantle the walls and floors.

What prompted Lambert to go on a shooting spree while the lawsuit was still ongoing is unclear, even to his lawyer Joel Braithewaite.

The attorney said Lambert 'was in a good place' when he spoke to him a day or so before the shooting, and the case had a successful deposition last week.

Lambert was due to give a speech in Orlando, Florida, later this week, and start a new job on Monday.

However, Lambert reportedly confessed to the murders when one of Stuart's colleagues at Metropole called him after the shooting to check on his welfare.

She said that he told her he was tired of the mold and water damage, and the only way anyone would pay attention was if he took drastic measures.

A bullet hole seen in a window of the apartment complex

A male victim died after being shot inside VIDA Fitness in Logan Circle on Thursday. The suspect is believed to be a member of the gym, police said 

Witnesses to the horrifying shooting spoke of seeing the building manager gunned down and others nearby wounded, and the panic and chaos that followed. 

A gymgoer said the scene inside the gym was 'horrific' and people were unable to escape the area where the shooter was without passing him. 

She said a man near her was shot while she was walking on the treadmill. 

Max Smith told NBC Washington that he left his apartment after a fire alarm went off. But when residents got outside, they heard gunfire. 

'Everyone starts sprinting,' he told the outlet. 

Smith said he heard at least three to four gunshots and said at least ten people barricaded themselves inside Call Your Mother deli's bathroom. 

'I'm very shaken up, you don't expect it,' he told the outlet.