The morning after the break-in, the thieves were not the only ones trying to guess the value of the stolen art. When the news broke, journalists made several eye-catching estimations as to what the art was “worth” — by which, in general, they meant the open-market potential of the stolen work, rather than its new black-market value. (The Independent produced a stratospheric number: 250 million English pounds, or about $400 million.)

Image Eugen Darie pleaded guilty to stealing paintings from a Dutch museum. Credit... Bogdan Cristel/Reuters

Most experts made cooler appraisals of what the works could raise at auction. The Monets were not paintings but pastels, which might sell for hundreds of thousands of dollars. Picasso’s “Head of a Harlequin” was a late-period “pen and brush,” not an oil painting, unlikely to command more than $2 million. Neither the Gauguin nor the Matisse was from each painter’s most notable period, and Meyer de Haan is a lesser figure. Lucian Freud’s “Woman With Eyes Closed” was the gem of the lot: a haunting work with an unpredictable auction value. Over all, however, the consensus was that the paintings might have raised between $10 million and $15 million in sales.

The initial lofty estimations in the media seemed harmless, but some art-recovery specialists thought them irresponsible. There is a black market for stolen artworks, and according to the head of the F.B.I.'s art-crime team, Bonnie Magness-Gardiner, their prices are inevitably a small fraction of the works’ legitimate value. Some estimates put the average at 7 to 10 percent of perceived open-market value. Criminals, presumably, read newspapers — and newspapers had drastically inflated the value of the Kunsthal’s missing works.

When Dogaru and his partners tried to sell them, though, they did not appear to have employed such rigorous math. Over the next few weeks, their prices ranged from tens of millions of euros for a single painting, when they were feeling optimistic, to 100,000 euros (or $134,000) apiece, as they became more desperate.

According to the indictment, Darie and Dogaru traveled to Brussels on Oct. 16, after the heist, to see a man known as George the Thief. They asked if he knew anybody who might be interested in some stolen paintings. After returning to Rotterdam the same day, they realized that their burglary had provoked a media frenzy and decided to travel separately to Romania. The canvases, stuffed in pillow cases, were driven by Darie.

In the ensuing months, Dogaru tried to sell at least some of the works in Romania. He did not cut a sophisticated figure: he carried the art in plastic bags and at one point showed that he was unable to spell the names of the artists. According to the indictment, Dogaru and Darie also tried to find buyers in France, Belgium, Monaco, Belarus and Russia — often through George the Thief. None of these attempts were successful. In November, however, the burglars’ advances to an art dealer in Bucharest resulted in two of the works being independently verified by Mariana Dragu, an expert from the Romanian National Art Museum. After Dragu recognized that the paintings were genuine, and therefore likely to have been stolen, she contacted the authorities, which prompted a police investigation of Dogaru and his accomplices.

The closest Dogaru came to selling any pictures came immediately before his arrest. A Romanian wine producer sent word that he was willing to buy four of the paintings. Dogaru, anxious to sell, priced them at 100,000 euros each. In fact, the wine producer was working with Romanian prosecutors, and the would-be sale was a sting operation. At the 11th hour, Dogaru was tipped off, and he canceled the meeting. In any event, Dogaru, Bitu and Darie were arrested soon afterward, in late January. Adrian Procop is still at large.