D.C. gunman blamed deadly condo shooting on years of unresolved mold, water damage

• A 55-year-old emergency room doctor shot five people at a Northwest Washington condominium complex on Thursday.
• He killed a building manager and wounded four others before dying by suicide.

The gunman who killed one person and wounded four others at a Northwest Washington condominium complex on Thursday blamed the attack on years of frustration over unresolved water damage and mold in his apartment, according to a building manager who spoke with him minutes after the shooting, US media reported.

Police identified the shooter as 55-year-old Matt Lambert, a board-certified emergency room physician and medical consultant who lived in a seventh-floor penthouse at the Metropole in the Logan Circle neighborhood.

Lambert was later found dead inside his unit from a self-inflicted gunshot wound.

The police and witness accounts said that the rampage began around 8 a.m. inside the Vida Fitness gym on a lower level of the building.

Security footage showed Lambert shooting 46-year-old building manager James Stuart point-blank in the back while Stuart was working out. Four other people were wounded in the attack.

Around 9 a.m., another Metropole building manager, Charelle Ferguson, called Lambert while checking on residents following the gunfire.

Ferguson told The Washington Post that Lambert answered and complained that mold and water leaks had made his unit unlivable.

"The only way people will pay attention, you have to do something," Lambert told her, before confessing that he had shot five people.

Property records show Lambert purchased the one-bedroom penthouse for nearly $1.1 million in 2016.

In 2025, he filed a lawsuit seeking at least $300,000 in damages against the condo association and EJF Real Estate Services, alleging they ignored water infiltration and mold following exterior building work in 2024.

The condo association and management company denied liability in court filings, attempting to shift blame to the ground-floor gym's exhaust system, a claim Vida Fitness owners rejected.

Investigators and acquaintances also pointed to an X account named "OfMiceandMold," believed to belong to Lambert, which documented months of grievances, court filings, and photos of his apartment draped in plastic tarps. At 8:06 a.m.

My manifesto is an engineering report https://t.co/B85qOQzioO

— OfMiceandMold (@miceandmold) November 12, 2026

Thursday, around the time the shooting began, the account posted an engineering report detailing failed repairs in "Dr. Lambert's" unit with the caption: "My manifesto is an engineering report." Earlier posts from April and May had specifically noted Stuart’s routine visits to the building's gym.