On September 24, 1991 – three days after he had last been seen alive leaving his house in the Boston suburb of Revere – his bound, beaten, and stabbed body was found in the trunk of his Cadillac, a short distance away.

[3] That year he was convicted and sentenced to prison for his role in the armed robbery of cash and furs from a Boylston Street furrier.

[4] Later, during the 1970s, Joseph Barboza recognized the brothers' prominence in the Boston mob by using their name as his alias after he moved to San Francisco, where he was killed in 1974.

[5] In the early 1970s, Donati became friends with Myles Connor Jr., a former rock musician and son of a Milton police officer who had turned to art theft as a career.

While Connor was out on bail, he arranged for the theft of a Rembrandt from the Boston Museum of Fine Arts in which he later claimed Donati had taken part;[8] in exchange for its return he received a reduced sentence.

The two frequently visited the Isabella Stewart Gardner Museum, as they had done since the early 1970s, noting how weak the security was given the expensive artworks within it.

[8] Connor and Donati went as far as to climb nearby trees and time the guards' movements through the various galleries during the night hours when the museum was closed.

The subsequent revelation forced Patriarca to step down, supposedly at the behest of Mafia families in other regions of the country, and escalated hostilities between the two factions.

Shortly after 1 a.m. on March 18, thieves disguised as police officers convinced security guards at the Isabella Stewart Gardner Museum in Boston to let them in, whereupon they bound the two men up and spent the next several hours removing 13 works, including Storm on the Sea of Galilee, Rembrandt's only known seascape, as well as the finial that Donati had indicated an interest in.

In August he told one friend that he had noticed two men wearing black jogging outfits near the house he was renting on Mountain Avenue in Revere, apparently tracking his movements, and believed they were preparing to make an attempt on his life.

Three days later his body was found in the trunk of the Cadillac he had been driving, on Savage Street in Revere, a short distance from his home.

[14] It is believed by law enforcement that Donati was likely murdered by other mobsters loyal to Salemme, possibly in retaliation for involvement, actual or perceived, in the failed attempt on their boss's life two years earlier.

Writer Ulrich Boser wrote in his 2009 book The Gardner Heist that it was "widely rumored" that at the time of his death Donati was preparing to tell police what he knew about it.

[14] In Kurkjian's 2015 book Master Thieves, he writes that Donati's sister Lorraine believes the brutality of her brother's killing suggests it was motivated by more than being on the wrong side in a gang war.

"[19] From the day of the Gardner Museum theft, Donati was believed to have had a role in it, possibly as one of the two thieves who, wearing what appeared to be police uniforms, took the guards captive and stole the works.

In 1997, Connor told Vanity Fair that he believed Donati had taken the gu, the oldest work in the museum's collection, to present to him as a gift later.

[8] He also told Kurkjian that shortly after the theft, he was visited at the Lompoc federal prison in California by David Houghton, another suspect in the case.

[9] In 1997, Boston Herald reporter Tom Mashberg was taken by a source, William Youngworth, an antiques dealer who had served as a fence for property stolen by Connor and Donati, among others, to a Brooklyn warehouse where he was allowed to see what he believed to be Storm on the Sea of Galilee; tests of paint chips he was allowed to take were only able to demonstrate that it dated from that era.

[15] Kurkjian offered another explanation for why Donati robbed the museum: he felt unsafe on the streets as long as Ferrara remained in custody, and hoped to use the art to bargain for his freedom, as Connor had done to reduce his sentence by arranging for the return of the BMFA's Rembrandt 15 years earlier.

The caller asked that Kurkjian not identify him in print and said he knew Ferrara, who had by then been released from prison but was declining interview requests.

After Kurkjian explained to him the FBI's current theory of the case, that Turner had masterminded the crime, the caller told him that was all wrong and that Donati had stolen the paintings "to get Vinnie Ferrara out of jail",[24] consistent with an earlier claim for the theft's motive in a 1994 letter to the museum that former director Anne Hawley considered to have been a genuine attempt to make a deal to return the paintings, since its writer had information about the thefts that was not public at the time.

[25] Kurkjian's caller said Donati visited Ferrara at the federal lockup in Hartford, Connecticut, where he was being held, after his January 1990 arrest on racketeering charges.

[23] The FBI, which continues to investigate the theft, has said it is no longer interested in identifying the thieves as the statute of limitations on the crime[clarification needed] expired in 1996 and no one can be prosecuted for it (although those knowingly in possession of the stolen works could still be charged for that offense).