Empty frames remained on display in 2011 at the Isabella Stewart Gardner Museum in Boston, more than 20 years after thieves took 13 works of art. including "Storm on the Sea of Galilee," which had been in the spot at left, by Rembrandt, and "The Concert," by Vermeer. (Josh Reynolds/AP)

Twenty-five years ago this week, as Boston’s St. Patrick’s Day revelries eased into the wee hours of March 18, 1990, two men impersonating police officers entered the Isabella Stewart Gardner Museum and made off with 13 works of art valued at up to $500 million. It is the most expensive art heist in U.S. history and is currently the second-longest unsolved case on the FBI’s “Top Ten Art Crimes” list. That the Gardner theft is still an open case is a “disgrace,” according to journalist Stephen Kurkjian, who draws on fresh evidence in “Master Thieves” to reveal his own chief suspect, tell the full story of the theft and perhaps hasten the missing works’ return.

Kurkjian clearly knows how to work his beat — he won three Pulitzer Prizes while at the Boston Globe. For this book, he interviewed low-level criminals long suspected of the crime and he reached out to mob bosses for answers. And most impressive, he delivers the story of Louis Royce, who discovered the museum’s security lapses while sneaking into the galleries during his troubled teen years. Royce claims that he passed that information along to his criminal connections and that someone picked up his tip and carried out the heist.

Placing the theft in historical context, Kurkjian charts the evolution of Boston’s gang wars in the 1980s and details how criminals have used stolen art to bargain plea deals. He also looks at the Gardner’s security issues, everything from troubles with the museum’s board to personnel lapses, and he examines failures in the FBI’s treatment of art crimes, building stark comparisons to more-successful European approaches. Notorious gangster Whitey Bulger’s story lurks along the edges of the narrative, and Kurkjian argues that Bulger’s capture in 2011 and the hunt for the Boston Marathon bombers in 2013 provide models for how crowdsourcing might be used to locate the missing Gardner masterpieces. Kurkjian has gathered so much information that explaining the smallest bit of it leads to a spate of cross-references, qualifications and digressions.

Unfortunately, this hurts as much as it helps. People and events are often mentioned casually before being formally introduced or explained. Several stories are repeated, occasionally several times, with similar phrases; for example, a tense closing scene when a key suspect asks Kurkjian to turn off his recorder might have held some suspense if Kurkjian hadn’t told the same story 86 pages before. Structural choices — and maybe bulldog competitiveness — further dull the storytelling. As the section on “The Heist” transitions to “The Search,” readers might expect to plunge into the investigation, but Kurkjian leaps instead to 1997, when Tom Mashberg, then at the Boston Herald, reported that he’d seen one of the stolen paintings — a claim that has been largely discredited. As for the revelation about the identities of these master thieves, Kurkjian’s detective work yields promising claims, but the FBI seems uninterested when he delivers his findings. Kurkjian never discovers why — and we’re left similarly in the dark.

Has “Boston’s last best secret” finally been explained? For now, those frames at the Gardner still hang empty. To that end, “Master Thieves” may be less the “final chapter” of this story than just the next one.

"Master Thieves: The Boston Gangsters Who Pulled Off the World’s Greatest Art Heist" by Stephen Kurkjian (PublicAffairs/PublicAffairs)

Taylor writes mystery stories and teaches at George Mason University.

The Boston Gangsters Who Pulled Off the World’s Greatest Art Heist

By Stephen Kurkjian

PublicAffairs. 272 pp. $25.99