An unsolved murder in 1991 is being revisited by authorities for possible clues into the infamous art heist at Boston's Isabella Stewart Gardner Museum, reports Bob Ward for Boston 25 News.

In the over three decades since thieves made off with treasured artworks valued then at $500 million, including a rare Vermeer and Rembrandt's only seascape, investigators have looked into the security guards, New England crime figures and others as culprits. The March 1990 heist of 13 still-missing artworks has been the subject of numerous documentaries, podcasts and searches, and a $10 million reward was offered by the FBI for the art's return.

But a recent tip has authorities newly revisiting the murder case of career criminal Jimmy Marks, who had links to other heist suspects.

According to Gardner Museum Security Chief Anthony Amore, Marks had been heard bragging about possessing two of the stolen paintings and saying that he had hidden some of the stolen artworks, reports Edmund H. Mahony for the Boston Herald.

Soon after his indiscretion, in February 1991, Marks was shot twice in the back of the head outside his apartment in Lynn, Mass.

Marks was an associate of mobster and heist suspect, the late Bobby Guarente, and met with him at his Maine home before he was killed.

After Marks' murder, Mass. State Police investigators discovered Guarente met at a diner in Saugus with another prime suspect, Robert Gentile, and two mob associates from Connecticut. Gentile, thought to be the last person possibly associated with the heist to still be alive, died of a stroke in September 2021. He allegedly was involved with some of the art being moved from Connecticut to Philadelphia, and then offered for sale, according to a 2013 statement from the FBI.

Authorities are now probing Marks' connection to the crime.