Two years ago this month, two individuals snuck red and black paint into the National Gallery of Art and used it to vandalize the protective case and pedestal exhibiting Edgar Degas’s Little Dancer Aged Fourteen. Yesterday, a federal jury found Timothy Martin, one of those individuals, guilty on two felony counts—causing injury to National Gallery property and participating in a conspiracy to do so. The other individual, Joanna Smith, earlier pleaded guilty to the first count and was sentenced. With Martin’s conviction, we have seen justice served in this matter.

Little Dancer Aged Fourteen is 144 years old and timeless. A wax sculpture, she is one of the most vulnerable and fragile works of art in the National Gallery’s collection. Mr. Martin and Ms. Smith’s violent treatment of her protective barrier has forever jeopardized her stability. More than $4,000 were spent on her immediate repair and cleanup. Visitors were denied the opportunity to view her for ten days while National Gallery staff examined the sculpture and cleaned and repaired the exhibit. The time spent planning to prevent such further incidents, as well as the impact these changes have on our staff and visitors’ experiences, are immeasurable.

With increased frequency, institutions—overwhelmingly nonprofit museums for the public benefit—have suffered collateral damage at the hands of agendas that have nothing to do with museums or the art attacked. The real damage that these acts of vandalism pose must be taken seriously to deter future incidents that continue to threaten our cultural heritage and historic memory.

The National Gallery is grateful to the US Attorney’s Office, the FBI’s Art Crime Team, and the US Park Police for taking these crimes seriously and for their dedicated efforts throughout the investigation and in prosecuting these individuals. As this conviction shows, these attacks on museums—and the unique treasures of our culture and history that we hold in the public trust—are neither inconsequential nor victimless crimes.