Prosecutors in Washington are dropping charges against three more defendants who had been accused of vandalizing the Lincoln Memorial Reflecting Pool.

The motions to dismiss the three misdemeanor cases coincide with the decision last week to drop the most serious of the cases, the felony prosecution of a former Olympian who prosecutors had accused of damaging the pool.

The U.S. attorney, Jeanine Pirro, abruptly abandoned the four cases after investigators concluded that botched work by a contractor, not vandalism, was the primary cause of “widespread damage” to the pool’s new blue lining.

President Trump has been fixated for months on the condition of the Reflecting Pool, which has been plagued for years by water leaking out between its long concrete slabs. This year, the Interior Department, which oversees the site, gave a no-bid contract to fix the pool to Atlantic Industrial Coatings, a small Virginia firm.

After pieces of the pool’s new blue lining began to peel up, the president and administration officials blamed several people who had been arrested and charged with vandalizing the pool.

But the extraordinary motions filed in District of Columbia Superior Court over the last few days indicated that the problems that had drawn the president’s ire were caused by a faulty repair job, not vandals.

David Hearn, a former Olympic canoeist, was the one defendant who was facing a felony charge, and on Friday, it was his case that the U.S. attorney’s office moved first to dismiss.

Ms. Pirro’s filing on Friday said that prosecutors had determined “the damage was the result of a botched installation and not vandalism.”

Along with Mr. Hearn, prosecutors moved to drop charges against three others: Justin Carreno, Sophie Dennison-Gibby and Cameron Thiers, who all were charged with destruction of property less than $1,000.

G. Allen Dale, who represents Mr. Thiers, said prosecutors had contacted him in an email to state their intent to drop the case.

“Mr. Thiers and I are both very happy this case is over. It probably shouldn’t have been brought in the first place,” Mr. Dale said in a phone interview Monday. “At least this nightmare is over for him.”

On Friday, Ms. Pirro said Interior Department officials initially misled prosecutors by blaming vandals for damage, when, in fact, the new blue coating installed by contractors had actually started to fail within two days of the project’s completion.

Ms. Pirro blamed Atlantic Industrial Coatings for a “flawed installation” and the administration’s rush to complete the project ahead of the America 250 celebration on July 4.

Earlier this summer, federal officials said at least seven people had been accused of vandalizing the pool. But the identity of the other people and the status of any cases against them could not be immediately determined.

Timothy Lauer, a spokesman for the U.S. attorney’s office, declined to comment.

Jamison Koehler, a lawyer who represents Ms. Dennison-Gibby, said his client was “relieved” the charges were being dropped after she had faced threats of jail time and had been “petrified to learn the President of the United States was threatening to bring full force of the U.S. criminal justice against her and others.”

Mr. Koehler added that while the case has been dropped for now, he considers a possibility a charge could resurface.

“This administration is so petty and manipulative, there is always the fear that they might,” he said.