The FBI is for a third time conducting a search of the Manchester, Conn., property of elderly mobster Robert Gentile, according to The Boston Globe. A convicted felon, Gentile has long been suspected of knowing details about the 1990 heist of a half-billion dollars worth of art from Boston's Isabella Stewart Gardner Museum.

On Monday, agents and evidence-sniffing dogs went to Gentile's home which was previously searched in 2012 and another time prior to that. Gentile allegedly tried to sell the Gardner artworks to an undercover FBI agent in 2015, but the deal did not happen.

While Gentile has denied any knowledge of the missing art, he had ties with other gangsters who are now linked by the FBI to the theft. Some of the artwork was said to be last seen in Philadelphia in 2000, but many of the FBI's prime suspects are dead, leaving Gentile as the last hope for information.

Among the Gardner's 13 missing works of art, for which there is a $5 million reward:

• Vermeer, The Concert
• Rembrandt, A Lady and Gentleman in Black
• Rembrandt, The Storm on the Sea of Galilee
• Rembrandt, Self-Portrait
• Govaert Flinck, Landscape with Obelisk
• Manet, Chez Tortoni
• Degas, La Sortie de Pesage
• Degas, Cortege aux Environs de Florence
• Degas, Program for an artistic