Authorities say DC gunman held long-standing feud with building management: What to know

Before the suspect, who police identified as Matt Wade Lambert, opened fire at a Washington, D.C., gym, killing his building manager, the 55-year-old medical doctor harbored a long-standing grievance with the building’s condominium association and management and had taken legal action for water damage and mold, according to court documents.

Lambert appeared to have operated an account on X since September 2025 focused on his alleged housing issues.

In at least one post, he appears to reference the man police say he fatally shot– building manager James Stuart.

The posts include numerous photos and videos he claimed show water damage and mold in his unit, and what he alleged are his attempts to seek redress with his building’s management.

On May 19, he wrote, “Saw my building manager at the gym today and he stated no knowledge of the audit.”

On Oct. 1, he appeared to reference Luigi Mangione , writing about his ongoing dispute with the building, “After months of ‘Luigi’ tactics (delay, deny, defend) by the HOA, we were finally able to submit an independent engineering report into the record. The report addresses 704, the facade rehabilitation more broadly, and lists other units affected. When the time is right, I will share the report on X, with other Metropole owners, and with Logan Circle realtors.”

A post referencing that report appeared on the account shortly after 8 a.m. on the morning of the shooting.

Lambert’s complaints appeared to have elevated beyond social media reports.

A complaint filed by Lambert against his condominium association in March 2025 in the Superior Court of the District of Columbia alleged mold and moisture and accused the association of negligence, among other counts.

The building’s management, EJF Real Estate Services inc., is also listed as a defendant in an amended complaint.

In the defendant’s response to the amended complaint, the condominium association and EJF Real Estate Services offered several affirmative defenses including the plaintiff “fail[ed] to state a claim upon which relief can be granted” and the defendants “did not owe a duty of care to the Plaintiff with respect to the issues alleged.

ABC News has reached out to an attorney who was representing Metropole Condominium Association in the dispute.

In a statement to ABC News, EJF Real Estate Services remembered James Stuart as “respected and beloved member of our team.” 

The company said Stuart “lost his life in a senseless act of violence.”

The management company said  the investigation is ongoing, and they would not comment on the details of the investigation.

Lambert would bring his grievances to the media, too.

Michael Brice-Saddler, a reporter who previously interviewed Lambert about the dispute, said in an interview with ABC News on Thursday that “[Lambert] felt like he’d been wronged, he felt like he shouldn’t have to pay for mistakes, he felt like were the fault of the building, and he tried to prove that in whatever way he could through court.”

Joel Braithwaite, an attorney for Lambert, spoke with ABC News Washington, D.C., affiliate WJLA on Thursday, saying he was “shocked” by the events that transpired.

Braithwaite said Lambert had recently gained new employment, and days prior had presented at a conference on artificial intelligence and healthcare.

“He is not someone that, to my mind, will possess any sort of destructive intent or ill will towards anyone, and so I’m very shocked and saddened that we are here today having this conversation,” Braithwaite said.

In a press conference on Thursday, Interim Chief of Police for the Metropolitan Police Department Jeffery W. Carroll cited the building dispute as a possible motive for the shooting.

Authorities said they were aware of an “ongoing dispute between the suspect in this case and the building condo homeowner’s association management regarding maintenance issues, mold and the like.”

Negotiators who spoke with the suspect mentioned that “most of the conversation was about the homeowner’s association and challenges with that,” Carroll said.

Lambert opened fire inside a Washington, D.C., gym on Thursday, according to police.

He then fled to his apartment, where he fired at more people from his balcony before turning a gun on himself, Carroll said at a press conference.

Officials said one of the injured was critically wounded andLambert died following a self-inflicted gunshot wound after barricading himself inside his apartment.