"We have identified the thieves who are members of a criminal organization with a base in the mid-Atlantic states and New England," said Richard DesLauriers, special agent in charge of the FBI's Boston office.
On the night of March 18, 1990, two thieves posed as Boston police officers. Once inside the museum, they tied up the guards and left with 13 masterpieces, including works by Degas and Rembrandt, valued at a total of $500 million.
The statute of limitations has since run out on the theft and officials have said naming the suspects would be "imprudent," given the continuing effort to recover the art work. DesLauriers said the announcement today, on the 23rd anniversary of the heist, was intended to increase public awareness, possibly leading to the artwork being found.
"The FBI believes with a high degree of confidence in the years after the theft the art was transported to Connecticut and the Philadelphia region and some of the art was taken to Philadelphia where it was offered for sale by those responsible for the theft," DesLauriers said.
There was an attempted sale of the art 10 years ago, but after that the FBI has limited knowledge of the whereabouts of the artwork, DesLauriers said.
He said that authorities plan to continue their search in the Philadelphia and Connecticut areas, but "with this announcement, we want to widen the 'aperture of awareness' of this crime, to the reach the American public and others around the world."
The announcement today marks a huge break in the case for the Isabella Stewart Gardner Museum, where 13 empty frames have hung on the walls for the past 23 years.
Anthony Amore, the museum's chief of security, highlighted a $5 million reward for "information that leads directly to the recovery of all of our items in good condition."
Although the statute of limitations has run out, anyone in possession of the paintings could still be held criminally liable, according to U.S. Attorney Carmen Ortiz.
Authorities urged those who are in possession of the art to turn it in, whether they leave it at a church, go through an attorney, or find another way to anonymously return it.
"As we have said in the past, the U.S. Attorney's Office will consider the possibility of immunity from criminal prosecution for information that leads to the return of the paintings based on the set of facts and circumstances brought to our attention. Our primary goal is, and always has been, to have the paintings returned," Ortiz said.
1990 Heist Stunned the Art World
During the early hours of March 18, 1990, two men disguised as police officers were let inside the museum through a security door. The museum's guard was told the officers were responding to a call.
Once inside, the thieves asked the guard to step away from the security desk, saying there was a warrant for his arrest. The move kept the guard more than a safe distance from the museum's emergency alert button.
The other guard was called to the security desk, where the thieves handcuffed the workers and marched them into the basement. The men were secured to pipes and their hands, feet and heads were duct-taped.
When the guards' morning replacement arrived, he discovered 13 pieces of art were missing, including work by Degas, Rembrandt, Manet and Vermeer.
In May 2012, authorities searched the Connecticut yard of an alleged mobster, hoping to find the paintings, however they were unsuccessful.
The FBI's specialized Art Crime Team, which has 14 special agents, has been dedicated to the case.