DC gunman held long-standing feud with building management over mold, authorities say: What to know

Dispute over water damage

Before the shooting, Lambert, a 55-year-old medical doctor, had pursued legal action over water damage and mold in his unit, according to court documents. His social media posts included photos and videos he said showed the damage and his efforts to seek a remedy from building management.

An amended complaint lists EJF Real Estate Services, the building’s management company, as a defendant. In their response, the condominium association and EJF raised defenses, including that the complaint failed to state a claim and that they owed no duty of care regarding the issues alleged.

Posts described ongoing conflict

In an October 1 post, Lambert referenced his dispute with the homeowners association and said an independent engineering report had been submitted to the record. He wrote that it addressed unit 704, facade rehabilitation and other affected units, and said he would share it later.

At least one post appeared to refer to James Stuart, the building manager police say Lambert fatally shot. The posts also included material Lambert presented as evidence of water damage and mold in his unit.

Police cite possible motive

Interim Metropolitan Police Department Chief Jeffery W. Carroll cited the building dispute as a possible motive at a Thursday news conference. Negotiators told police that much of their conversation with Lambert concerned the homeowners association and its challenges, Carroll said.

Colleagues and management respond

EJF Real Estate Services described Stuart as a “respected and beloved member of our team,” in a statement to ABC News. The company said the investigation was ongoing and declined to comment on its details.

Reporter Michael Brice-Saddler, who had previously interviewed Lambert about the dispute, said Lambert felt he had been wronged and tried to prove in court that the building was responsible for the problems. Braithwaite said Lambert had recently found new employment and presented at a conference on artificial intelligence and healthcare days earlier; Braithwaite said the news was shocking and saddening.