DC gym shooting: Shooter complained about mould, water damage in apartment before attacking

A man who opened fire at a gym inside a luxury condominium building in Washington DC, killing the building manager and injuring four others, had repeatedly complained about mould and water damage in his apartment before the shooting, police said. The gunman, identified as 55-year-old Dr Matt Lambert, later shot himself inside his apartment following a standoff with police. Three firearms were recovered from the apartment, according to law enforcement sources cited by CBS News. The shooting took place on Thursday morning at the Vida Fitness centre on the ground floor of the Metropole Condominiums in the Logan Circle neighbourhood. Police identified the person killed as 46-year-old James Stuart, who managed the building. An X account under the name @OfMiceandMold, which CBS News linked to Lambert, contained dozens of posts detailing his grievances over alleged disrepair in his apartment. He had repeatedly criticised the building's contractors and property management company, EJF Real Estate Services, accusing them of failing to address problems with his unit.

'My manifesto is an engineering report'

Shortly before the shooting, Lambert posted what he described as an engineering report examining mould and water-related problems in the building. "My manifesto is an engineering report," he wrote on X. In an October 1 post, he appeared to refer to the 2024 killing of UnitedHealthcare chief executive Brian Thompson by Luigi Mangione. Lambert 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." He also said he would share the report on X "when the time is right". In another social media post dated April 28, Lambert wrote, "If you're looking for the building manager, I would check the gym." Lambert had filed a lawsuit against the Metropole Condominium Association, alleging damages of more than $290,000 as of May. The association and EJF denied responsibility, arguing that any damage had been caused by third parties beyond their control and that Lambert had failed to limit his losses.

Witnesses describe chaos during shooting

Police said Lambert opened fire inside the building's gym before returning to his apartment, where he remained during a standoff with officers and eventually killed himself. A woman who was exercising on a treadmill when the shooting began told CBS News that she had to evacuate by passing the area where one of the victims 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." Another witness, who lived directly below Lambert and was about 20 feet from the shooting, said the suspect had become increasingly upset during homeowners' association meetings. He said Lambert had previously invited residents into his apartment to show them the condition of the unit. The witness described the 99-unit condominium as a "tight-knit community". During the shooting and police standoff, his girlfriend barricaded herself inside their apartment. He said the flat was subsequently left under an inch of water following the firefighting response.

Doctor had bought penthouse for $1.1 million

Lambert had purchased the condominium in September 2016 for $1,095,000, according to Washington DC tax records. Court documents showed that he owned a penthouse unit in the building.

He ran MLEM, a healthcare and technology consultancy, and had studied medicine at Marshall University in West Virginia before completing his residency at West Virginia University, according to his LinkedIn profile. As per his personal website, Lambert is described as a board-certified emergency physician with more than two decades of clinical experience. The website also said he had volunteered in underserved communities in Kenya, Belize and Haiti. The shooting took place in the Logan Circle neighbourhood, where the Vida Fitness centre catered to residents of the condominium building. Police have identified the building manager as the person killed in the attack, while four others were wounded.