A social media account linked to the gunman who opened fire at a fitness center inside a luxury condominium building in Washington, D.C., on Thursday morning had been documenting complaints about mold and water damage in his apartment prior to the deadly attack, which authorities say was directed at the building’s manager. Multiple law enforcement sources have identified the shooter as Dr. Matt Lambert.
One person was killed and four others were wounded in the shooting at Vida Fitness, located in the Logan Circle neighborhood. Police identified the deceased victim as 46-year-old James Stuart.
Authorities confirmed that Lambert fatally shot himself inside his apartment following a standoff with police. Three firearms were subsequently recovered from the residence, according to law enforcement sources in Washington.
An account on X operating under the username @OfMiceandMold had functioned as a platform through which Lambert documented his grievances regarding the alleged deteriorating conditions of his apartment.
Across dozens of posts on X, Lambert expressed his frustration with the Metropole Condominiums’ building contractors, EJF Real Estate Services, alleging that the company had repeatedly failed to address ongoing issues within his unit. CBS News has reached out to EJF Real Estate Services for comment.
Lambert, who was 55 years old and operated a Washington, D.C.-based healthcare consultancy, had purchased the condominium in September 2016 for $1,095,000, according to D.C. tax records. Court documents further indicate that he owned a penthouse unit within the building.
Prior to the shooting, Lambert published what he claimed to be an engineering report examining mold and water-related issues within the building. “My manifesto is an engineering report,” he wrote in an accompanying post.
At one point, Lambert appeared to reference Luigi Mangione, who shot and killed UnitedHealthcare CEO Brian Thompson in 2024. On October 1st, he wrote, “After months of ‘Luigi’ tactics (delay, deny, defend) by the HOA, we were finally able to submit an independent engineering report into the record,” adding that he intended to share the engineering report on X “when the time is right.” Notably, Mangione had inscribed the phrase “delay, deny, defend” on the bullets used in that killing.
In a social media post dated April 28th, Lambert wrote: “If you’re looking for the building manager, I would check the gym.”
Lambert had also filed a lawsuit against the Metropole Condominium Association, outlining his grievances and seeking damages exceeding $290,000 as of May.
The Metropole Condominium Association and EJF denied responsibility for the alleged damage, asserting that any damage sustained was the result of third parties beyond their control, and that Lambert had failed to take reasonable steps to mitigate his losses.
Neither the Metropole Condominium Association nor EJF responded immediately to requests for comment.
Police confirmed that Lambert carried out the attack inside the Vida Fitness center, situated on the ground floor of the building and primarily serving its residents.
One woman, who had been using a treadmill at the time of the shooting, recounted hearing the gunshots and described being forced to evacuate through the area where one victim had been killed.
“There was no way of getting out of the gym other than going past that scene,” she said.
“It was like chaos. It was horrific, honestly.”
A witness who had been approximately 20 feet from the shooting told CBS News that he resided directly below Lambert and described the gunman as having grown increasingly agitated during homeowners’ association meetings. He noted that Lambert had previously invited neighbors into his apartment to witness firsthand the extent of the damage. The witness characterized the building as a “tight-knit community” comprising 99 units.
The witness further stated that during the shooting and the subsequent police standoff, his girlfriend had barricaded herself inside their apartment, which sustained approximately an inch of water damage as a result of the emergency response to a fire at the scene.
Logan Circle is a thriving Washington, D.C., neighborhood that underwent significant gentrification during the 2010s and is widely recognized for its historic architecture and some of the city’s most frequented restaurants and bars.
According to his LinkedIn profile, Lambert was the founder and chief executive officer of MLEM, a healthcare and technology consultancy. He earned both his undergraduate and medical degrees from Marshall University in West Virginia and completed his residency at West Virginia University, as indicated by his professional profile.
