Several former Iranian properties in Washington, D.C., are not being used exclusively for diplomatic purposes and should therefore be allowed to be confiscated to satisfy a civil judgment stemming from a suit that alleges Iran’s support of terrorism, a lawyer for a bombing victim argued Friday in a federal appeals court.

The lawyer, John Vail, senior litigating counsel for the Center for Constitutional Litigation in Washington, argued that the federal government’s periodic rental of the property — including Iran’s former embassy and the ambassador’s residence — has ended the diplomatic use of the real estate. Vail argued Friday before a three-judge panel of the U.S. Court of Appeals for the D.C. Circuit.