A judge in Washington has scheduled a trial in September for a man accused of vandalizing the Lincoln Memorial Reflecting Pool.
The man, David Hearn, is one of seven people who face charges, federal authorities say, in connection with what President Trump has said were efforts to sabotage his administration’s renovation of the pool. Mr. Hearn, 67, is the only person known to be facing a felony charge, rather than a misdemeanor.
Mr. Hearn, a former U.S. Olympian, has pleaded not guilty to a charge of destruction of property. During a hearing on Monday in D.C. Superior Court, he spoke only to confirm his name and to say that he understood he must appear at trial.
The judge, Todd E. Edelman, scheduled the trial to begin on Sept. 28.
The Trump administration’s push to renovate the pool has stirred criticism over the cost and over the wisdom of trying to eradicate the algae that the president finds so bothersome.
Mr. Hearn was arrested last month after the police said he had peeled blue-tinted waterproofing off the pool floor. The coating had begun to peel several days before, according to internal government documents.
After his arrest, Mr. Hearn said that he had reached down to touch a peeling blue strip out of curiosity. His lawyer said that his actions were not criminal conduct.
Several other people alleged to have engaged in similar acts were given citations ordering them to appear in court but were not charged with a felony offense, which carries a longer potential penalty.
Last week, Mr. Hearn’s lawyers filed a motion to dismiss the case asserting that the “government has failed to preserve the key physical evidence in this case: the Lincoln Memorial Reflecting Pool, including the section of its liner that Mr. Hearn is charged with damaging.”
At the hearing on Monday, Judge Edelman did not grant the defense motion to dismiss the case. But he cautioned prosecutors that the government “is sort of operating at its own peril with regard to this trial,” if work on the pool jeopardizes the defense team’s ability to analyze the site.
Prosecutors said they are doing what they can to preserve the condition of pool until defense experts can examine the site.
A visit to the pool on Monday found some work on the site continuing.
About 1:30 p.m. on Monday, a photographer for The New York Times, Andrew Leyden, took photos of a National Park Service crew pulling up sections of the pool’s blue lining with their bare hands. The pool was drained this month to allow the peeling liner to be repaired. In an interview, Mr. Leyden said he saw the crew remove sections in two places near the pool’s midsection.
Katie Martin, a spokeswoman for the Interior Department, said that the crews were there to inspect expansion joints — flexible buffers laid between the pool’s huge concrete slabs.
Asked about the court’s concerns about the defense team’s need to examine the site, Ms. Martin said: “As always, we will continue to follow all lawful orders. Other than that, we do not comment on pending litigation, especially not criminal matters.”
The pool’s renovation has so far cost about $16.4 million, and has entailed upgrading a water-purification system, sealing leaky joints between the pool’s concrete slabs and coating the slabs with a waterproofing material in a color Mr. Trump has called “American flag blue.”
The administration awarded no-bid contracts, saying they needed to expedite the project to have it completed by the nation’s 250th birthday on July 4.
But after officials removed devices used to combat algae, the water turned from blue to green and enormous algae blooms spread unchecked. Around the same time, pieces of the new blue lining were also seen peeling up and floating to the pool’s surface.
David A. Fahrenthold contributed reporting.
