WASHINGTON– A former Olympian accused of deliberately damaging the Lincoln Memorial reflecting pool is seeking access to all of the closed-door testimony that led to his indictment, pointing to “irregularities” in those grand jury proceedings.

In a court filing filed Monday, David Hearn’s attorneys requested an order that the government turn over a full transcript of all grand jury proceedings. They also want prosecutors to reveal the legal instructions they gave grand jurors about the elements of Hearn’s alleged crime.

Hearn pleaded not guilty earlier this month to felony destruction of property and has a trial scheduled to begin Sept. 28 in D.C. Superior Court. The charge, which carries a maximum prison sentence of 10 years upon conviction, accuses Hearn of causing at least $1,000 in damage to the pool.

But his lawyers question whether prosecutors adequately presented the grand jury with adequate evidence to support the amount of harm alleged in Hearn’s indictment. A National Park Service official testified that the pool was already damaged before Hearn allegedly touched it, could not quantify any damage attributable to Hearn and said the same repairs would have been required regardless of his conduct, defense attorneys said.

“The witness’s testimony established that the pool had substantial pre-existing damage that required repair prior to any alleged conduct by Mr. Hearn,” his attorneys wrote. “According to the witness, the pool was losing more than a million gallons of water per week; its expansion joints had exceeded their useful life; and the liner already contained a tear.”

Hearn’s attorneys base those arguments on their limited review of grand jury testimony. They want court-ordered access to all proceedings.

A spokesperson for U.S. Attorney Jeanine Pirro’s office in Washington did not immediately respond to an email seeking comment on Hearn’s arguments.

Hearn had previously asked the court to dismiss the case, which stems from the troubled multimillion-dollar renovation project championed by President Donald Trump. Their attorneys argued that the government has failed to adequately preserve important physical evidence from the Reflecting Pool.

Trump, a Republican, has claimed that vandals have damaged the pool, but critics of the administration attribute the problems to shoddy repair work. During a speech Monday at General Motors in Michigan, Trump claimed that a “sick” person cut the pool liner, but said the attraction is receiving treatment.

“He’s in the hospital now, but he’ll get better very soon,” Trump said. “It’s almost ready to open.”

Hearn and his supporters claim his prosecution is a politically motivated attempt by the Trump administration to deflect blame and scapegoat others.

Hearn told The Associated Press that he was detained by National Guard troops and U.S. Park Police for five hours after passing the pool during a bike ride on June 19. He said he walked over to examine the pool’s freshly peeled liner and briefly touched a piece stuck to the side of the pool, but said he obeyed a park worker who told him to let it go.

Hearn, 67, of Bethesda, Maryland, competed in three Summer Olympics and had his best finish, ninth, at the 1996 Atlanta Olympics, the United States Olympic and Paralympic Committee says on its website.

At least three other people have been charged in the same court with misdemeanors for allegedly removing chips of paint from the pool.

___ Associated Press writer Darlene Superville contributed to this report.