The theft occurred on March 18, 1990, when two men posing as police officers entered the museum and convinced a security guard to let them in. They handcuffed the guards in the basement and stole masterpieces including Vermeer's 'The Concert' and Rembrandt's 'Christ in the Storm on the Sea of Galilee', along with a Napoleonic eagle finial and the museum's security videotapes.
In 2013, the FBI said it knew who was responsible but declined to name them. Former FBI agent Geoff Kelly, who led the investigation for over two decades, has written a book identifying the men he believes were involved. Some tips pointed to the Irish Republican Army and Boston mob figures including Whitey Bulger. Kelly followed a lead to France where FBI agents posed as wealthy intermediaries, and a triple murderer known as 'Meatball' secretly recorded conversations with suspected associates.
The museum has offered a $10 million reward for information leading to the recovery of the artworks. Empty gilded frames of the missing paintings still hang in the museum, as Isabella Stewart Gardner stipulated in her will that nothing in the museum would be changed after her death.