Dr. Matt Lambert identified as shooter in DC gym attack

A local physician fired a gun inside a Washington, D.C., gym on Thursday morning.

Law enforcement officials identified the gunman as Dr. Matt Lambert. Two law enforcement sources and one other familiar person confirmed his identity to The Associated Press. They spoke on condition of anonymity.

Lambert entered the VIDA gym in the Logan Circle neighborhood around 8 a.m. He opened fire, killing one person and injuring four others. Officers shot and killed the gunman during the exchange.

Audio from the initial 911 call indicated that approximately 30 people hid in the basement during the shooting. The attack appears connected to a long standing dispute between Lambert and his building management.

Lambert sued the Metropole Condominium Association last year over the conflict. AP reporting notes that he maintained an active account on the social platform X under the handle OfMiceandMold. Less than ten minutes before the first emergency calls, the account posted a message stating, "My manifesto is an engineering report." The post included screenshots of a document detailing mold and water intrusion issues in his unit.

Earlier in October, the account holder criticized the association for employing "months of 'Luigi' tactics." The post referenced the submission of an independent engineering report. The account featured numerous photos and videos documenting the alleged problems. Officials describe the situation as an apparent dispute while the investigation continues.