On the morning of March 18, 1990, Rembrandt van Rijn’s The Storm on the Sea of Galilee (along with twelve other works) was stolen from the Isabella Stewart Gardner Museum in Boston. The theft, which rendered losses well over $500 million, remains unsolved for a quarter century—but a promising lead has recently taken the FBI to a sleepy town in Connecticut.

FBI officials believe that the art heist may be connected to alleged mobster Robert Gentile, who failed a lie detector test when asked about the stolen paintings. Cleared by a third search warrant, federal agents stormed his Manchester home on Wednesday. The 79-year-old, who was convicted of separate drug and gun related charges in 2015, is currently serving time in federal prison.

In a statement to ABC News, Gentile’s lawyer A. Ryan McGuigan said that his client continues to deny the allegations. “He laughed and he couldn’t believe they were at his house again,” McGuigan said in the interview. “And he said, this is a quote, ‘They ain’t gonna find nuttin.'”

Johannes Vermeer, The Concert (circa 1663–66). The painting was stolen from the Isabella Stewart Gardner Museum in 1990.

Rembrandt’s only seascape, while certainly rare, isn’t the only important painting taken from the museum’s collection. The robbery, after all, is cited as the largest property theft in history. Other pieces lost include five works by Edgar Degas, Johaness Vermeer’s The Concert (1664), and Edouard Manet’s Chez Tortoni (1878–1880). The full report is listed on the museum’s website.

Recovering the collection has been a big priority for the FBI’s art crime team. In a page exclusively dedicated to this case, the FBI is offering a $5 million reward for the return of the 13 artworks. What, if anything, the FBI recovered from their search has not yet been announced..