Boston Globe: Photo by Steven Senne/AP at FBI conference

The FBI and the Isabella Stewart Gardner Museum ­received a flood of tips from around the country Tuesday, as new details emerged about the turning point in the investigation of the notorious Gardner Museum heist 23 years ago. 

The latest, exhaustive phase in the inquiry is based on a tip that a caller made to authorities in 2010, according to Anthony Amore, the Gardner Museum’s head of security and chief investigator. 

He said Tuesday that the tip was so fruitful — leading to the announcement that investigators know the identities of the thieves and could trace the art from Boston to Connecticut and Philadelphia — that the FBI has since rededicated significant resources to investigating the heist. 

“That tip, plus thousands of man-hours, led to where we are today,” Amore said.

The latest focus has been on Robert Gentile, a 75-year-old ailing Mafia figure with ties to organized crime in Philadelphia and Boston. His Connecticut home was searched last year in relation to the heist. He was charged with drug dealing and possession of an illegal firearm in what his lawyer called a tactic by the FBI to pressure him to disclose information about the heist. 

Gentile, who pleaded guilty and is slated to be sentenced in May, faces a lengthy prison term. His lawyer, Ryan McGuigan, has maintained that Gentile knows nothing about the heist or the whereabouts of the artwork. 

But investigators seem to have trained their focus on Gentile in the recent phase of the investigation. 

A person with knowledge of the FBI investigation, who asked to remain anonymous ­because of the sensitivity of the inquiry, confirmed Tuesday that investigators found a list of the art stolen from the Gardner, and the estimated value of the works, during the search of Gentile’s home. The discovery of the list was first ­reported by The Hartford ­Courant. 

Gentile also had close ties to organized crime figures in Philadelphia and in Boston, including the late Robert Guarente, who has been tied to almost every­one mentioned as a person of interest in the heist. 

Guarente, for instance, was close with the late Carmello Merlino, who ran an auto body shop in Dorchester and who, according to FBI reports, once tried to negotiate the return of the artworks. No deal ever came to fruition, and Merlino was later convicted in a scheme to rob an armored car depot in Easton. He said that he was set up by informants and that the FBI was pressuring him for ­information regarding the Gardner heist. Merlino died in prison in 2005 at age 71. 

Two other men were also convicted in the armored car depot scheme and received lengthy prison sentences, though they have denied knowledge of the heist or the ­location of the artwork. ­Stephen Rossetti, 54, who is Guarente’s nephew, is slated to be released in 2044, and David Turner, 45, is set to be released in 2025. 

Guarente died in 2004 at age 65. His wife has told authorities in recent years that she saw him give Gentile at least one painting some time around 2003, around the time authorities say some of the art was offered for sale in Philadelphia. The wife, however, did not describe the painting as one of the works taken from the Gardner.

FBI: An empty frame in the Dutch Room of the ISGM

"As I have said many times in the past, this investigation is an excuse in finding 13 needles in a haystack by making the haystack smaller. The information we provided at the press conference shows that we continue this work, and that the haystack is smaller than ever."

Although it doesn't know the current whereabouts of the art, the FBI believes it might still be in the Philadelphia area. So the agency will launch a publicity campaign, soliciting tips using social media and, within a few weeks, putting up digital roadside billboards in and around Philadelphia, where it believes someone may have glimpsed—or even bought—the art without knowing of the tainted origin. The museum is offering a $5 million reward for a tip leading to the recovery. The theft represents the largest property crime in U.S. history, according to the FBI.

In a stunning development in the investigation of the world's richest art heist, law enforcement officials said Monday they know who stole $500 million in master works from Boston's Isabella Stewart Gardner Museum and disclosed new detail about their interest in Hartford mobster Robert Gentile.

"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," said Richard DesLauriers, Special Agent in Charge of the FBI's Boston office. "With that same confidence we have identified the thieves who are members of a criminal organization with a base in the mid-Atlantic states and New England."

But since 2010, Gentile has been questioned repeatedly about his membership in the Boston branch of a Philadelphia-based criminal organization, as well as leads that place at least some of the stolen paintings in Connecticut and the Philadelphia area.

FBI composite of paintings stolen from ISGM in 1990

On the 23rd anniversary of the largest art theft, an FBI press release announced: "FBI Provides New Information Regarding the 1990 Isabella Stewart Gardner Theft".

The FBI believes it has determined where the stolen art was transported in the years after the theft and that it knows the identity of the thieves, Richard DesLauriers, special agent in charge of the FBI’s Boston office, revealed for the first time in the 23-year investigation. “The FBI believes with a high degree of confidence that 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 added, “With that same confidence, we have identified the thieves, who are members of a criminal organization with a base in the Mid-Atlantic states and New England.” After the attempted sale, which took place approximately a decade ago, the FBI’s knowledge of the art’s whereabouts is limited. 

Information is being sought from those who possess or know the whereabouts of the 13 stolen works of art—including rare paintings by Rembrandt and Vermeer—by publicizing new details about the case and continuing to highlight the $5 million reward for the return of the art. Although the FBI does not know where the art is currently located, the FBI is continuing its search, both in and beyond the Connecticut and Philadelphia areas. “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,” said DesLauriers. 

Anthony Amore, the museum’s chief of security, noted that the reward is for “information that leads directly to the recovery of all of our items in good condition.” He further explained, “You don’t have to hand us the paintings to be eligible for the reward. We hope that through this media campaign, people will see how earnest we are in our attempts to pay this reward and make our institution whole. We simply want to recover our paintings and move forward. Today marks 23 years since the robbery. It’s time for these paintings to come home.” 

“The investigation into the Gardner Museum theft has been an active and aggressive effort, with law enforcement following leads and tracking down potential sources of information around the globe. Over the past three years, I have visited the museum several times, and each time I entered the Dutch Room and saw the empty frames, I was reminded of the enormous impact of this theft. I do remain optimistic that one day soon the paintings will be returned to their rightful place in the Fenway, as Mrs. Gardner intended,” said U.S. Attorney Carmen M. Ortiz. “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.” 

To recover stolen items and prosecute art and cultural property crime, the FBI has a specialized Art Crime Team of 14 special agents supported by special trial attorneys. The team investigates theft, fraud, looting, and trafficking across state and international lines, with estimated losses running as high as $6 billion annually. The FBI also runs the National Stolen Art File, a computerized index of stolen art and cultural properties that is used as a reference by law enforcement agencies worldwide. 

The FBI stressed that anyone with information about the artwork may contact the FBI at 1-800-CALL-FBI (1-800-225-5324) or the museum directly or through a third party, said Special Agent Geoffrey Kelly, who is the lead investigator in the case and a member of the Art Crime Team. “In the past, people who realize they are in possession of stolen art have returned the art in a variety of ways, including through third parties, attorneys, and anonymously leaving items in churches or at police stations.” Tips may also be submitted online at https://tips.fbi.gov. 

The publicity campaign announced today includes a dedicated FBI webpage on the Gardner Museum theft, video postings on FBI social media sites, publicity on digital billboards in Philadelphia region, and a podcast. To view and listen to these items, visit the FBI’s new webpage about the theft: www.FBI.gov/gardner.