Nearly 30 years after an elderly New York couple’s 1911 painting by Marc Chagall was stolen from their Manhattan home, the modernist oil-on-canvas work is being returned to the family’s estate.

The painting, entitled Othello and Desdemona, was recovered last year after a Maryland man contacted the FBI’s Washington Field Office. The man’s repeated efforts to consign the painting had been rebuffed by a Washington, D.C., gallery owner who was suspicious about the lack of paperwork supporting the painting’s authenticity and provenance. The gallery owner suggested the man call law enforcement, which is how it became an FBI investigation.

“We took the case from there,” said Special Agent Marc Hess, one of a handful of FBI investigators on the Bureau’s specialized Art Crime Team. Hess said the investigation led to the man’s home in Maryland, where he had stored the painting in his attic for years in a custom box he crafted out of a door jamb and plywood. Hand-scrawled on the top of box were the words “Misc. High School artwork.”

According to court documents, the Maryland man had obtained the painting in the late 1980s or early 1990s from the man who stole the Chagall in New York in 1988. The thief, it turned out, was a worker in the Upper East Side building where Ernest and Rose Heller lived in an apartment surrounded by paintings and sculptures by renowned artists like Renoir, Picasso, Hopper, and Chagall. Several other works of art also disappeared in the heist.

“It was an inside job,” Hess said. “A person who had regular access to the building was stealing from apartments while the tenants were away.”

Shortly afterward, the thief met with the Maryland man in Virginia to try to sell the painting, court documents show. The Maryland man found a potential buyer, but the deal collapsed when he learned he wasn’t going to receive a cut of the proceeds. The Maryland man kept possession of the painting and stashed it in his attic for years. He brought it out in 2011—and again in January 2017—in his fruitless appeals to the D.C. gallery owner to exhibit and try to sell the stolen art.

“Well documented and known art is very hard to move once it has been stolen,” said Supervisory Special Agent Tim Carpenter of the FBI’s Art Crime Team. “Gallery owners are our first line of defense in identifying pieces of art that do not have the appropriate documentation and should be brought to the attention of law enforcement.”

The Hellers, who bought the painting in the 1920s, have both passed away. The artwork, which shows Shakespeare’s titular Othello holding a sword and looking at his bride, Desdemona, lying on a bed, was painted by Chagall when the Belarusian painter lived in Paris. In 1967, the Hellers’ painting was on exhibit at the Kunsthaus Zurich in Geneva, Switzerland.

“They went on vacation back in 1988,” Hess said. “They returned, and this work of art—along with several others—was missing.”

The statute of limitations for the theft has expired, so no charges are pending against the individual who initially stole the painting, nor the individual who kept it. The Maryland man is not named in court filings. The suspected thief in the case was convicted in federal court and served time on charges related to selling stolen property, including art from other apartment buildings.

“The investigation into the other missing paintings continues,” Hess said. The Chagall painting, which until recently was still stored in the makeshift wooden box, will be returned to the Hellers’ estate, which plans to place it on auction. Proceeds will reimburse the insurance company that paid the theft claim years ago and be directed to several non-profit organizations supported by the estate, including an artists’ colony in New Hampshire.

“As the FBI returns this painting to the estate of its proper owners, we do so with the purpose of preserving history,” said Washington Field Office Assistant Director in Charge Nancy McNamara. “This piece of artwork is of significance not just for its monetary value, but for its place in the world of art and culture. The FBI continues to commit investigative resources to recover cultural property.”