Twenty-seven years after two thieves disguised as police officers talked their way into the Isabella Stewart Gardner Museum, tied up the guards and fled with masterpieces worth an estimated $500 milion, it remains the world’s largest art heist and one of Boston’s most baffling mysteries.

Isabella Stewart Gardner Museum, File / AP
"The Storm on the Sea of Galilee" by Rembrandt, one of more than a dozen works of art stolen by burglars in the early hours of March 18, 1990 from the Isabella Stewart Gardner Museum.
For 81 minutes during the early morning hours of March 18, 1990, the thieves pulled and slashed treasured works from their frames. They stole 13 pieces, including three Rembrandts, among them his only seascape, “Storm on the Sea of Galilee”; Vermeer’s “The Concert”; and works by Flinck, Manet and Degas.
In a puzzling twist, they walked by more valuable pieces, yet swiped an ancient Chinese vase and a bronze finial eagle from atop a Napoleonic flag.
None of the works have ever been recovered, despite the offer of a $5 million reward for information leading to their safe return and promises of immunity. And nobody has ever been charged with the crime. The FBI announced two years ago that it was confident it had identified the thieves -- two local criminals who died shortly after the heist -- but declined to name them.
The FBI said it believed the artwork was moved through organized crime circles to Philadelphia, where the trail went cold around 2003.

The investigation remains active and ongoing, according to Kristen Setera, a spokeswoman for the FBI’s Boston office, who urged anyone with information about the whereabouts of the missing works to contact the FBI, the museum, or a third party.
“We have determined that in the years since the theft, the art was transported to the Connecticut and Philadelphia regions, but we haven’t been able to identify where the art is right now,” Setera said.
Anthony Amore, the museum’s security director, said he remains hopeful that the artwork will be returned.
“We are still receiving tips and we really hope the public will send us what they know,” Amore said. “What we’re hoping for are facts, as opposed to theories.”
The heist has generated countless theories, involving a dizzying array of suspects, from Irish gunrunners and Corsican mobsters to a Hollywood screenwriter and petty thieves.
Here are some of the most intriguing theories considered by investigators over the years:
The Merlino crew:
The FBI has focused heavily in recent years on the theory that local criminals with mob ties were behind the heist, and said it believes that the two thieves who entered the museum died a short time later. The suspects frequented a Dorchester repair shop operated by Carmello Merlino, a mob associate who boasted to two informants that he planned to recover the artwork and collect the reward. Instead, he was caught in an FBI sting in 1999 and convicted of trying to rob an armored car depot. Despite offers of leniency in return for the stolen artwork, Merlino never produced it and died in prison in 2005.
The theory, outlined by the FBI in a PowerPoint presentation a couple of years ago, is that Merlino’s associates, George Reissfelder and Leonard DiMuzio, who both died in 1991, were involved in the theft, along with David Turner and possibly others. Reissfelder, 51, of Quincy, died of a cocaine overdose. DiMuzio, 43, of Rockland, was found shot to death in East Boston. Turner, 49, of Braintree, was convicted in the armored car robbery case with Merlino and is scheduled to be released from prison in 2025.
The FBI believes the stolen artwork ended up in the hands of Robert “Unc” Guarente, a convicted bank robber with ties to the Mafia in Boston and Philadelphia, who died in 2004.
In 2010, Guarente’s wife, Elene, told the FBI that shortly before her husband’s death, he gave two of the stolen paintings to a Connecticut mobster, Robert Gentile, during a rendezvous in Maine, according to authorities.
Eighty-year-old Gentile, who is in failing health and currently in jail awaiting trial on federal gun charges, was ensnared in two FBI stings and promised leniency in exchange for the stolen artwork. He insists he knows nothing about the stolen artwork. But authorities allege that he offered to sell the paintings several years ago for $500,000 each to an undercover FBI agent.