On May 19, 2003, a man in his late twenties walked along New Bond Street, in London, and stopped outside the flagship store of Graff, which proudly claims to sell “the most fabulous jewels in the world.” The man, whose image, captured by surveillance cameras, was later studied by detectives on three continents, was five feet eight and blond, with a small waist and the upper body of an acrobat. He spoke to no one, and did not go inside to look at the necklaces and rings on display. After five minutes, the man stepped away from the storefront and continued down the street.

Graff’s clients, who include Oprah Winfrey and Victoria Beckham, prize the store for its colored diamonds, including its yellow stones, which were considered tainted before Graff mounted a successful marketing campaign, and rare blue ones that acquire their tint from traces of boron. The man on the surveillance footage, Predrag Vujosevic, was not a typical Graff customer. Raised in Bijela, a fishing village in Montenegro, he was reputed to be one of the leaders of a spectacularly inventive, and elusive, gang of jewel thieves known as the Pink Panthers. Many élite jewellers, including Chopard and Harry Winston, can be found on this stretch of New Bond Street, which is a few streets north of Buckingham Palace; Vujosevic may have been attracted to Graff because he had a yen for colored diamonds, or because security at the store seemed lax.

On a recent visit to Graff, I was welcomed by a security guard who did not ask if I had an appointment or peek inside my leather satchel. Overt security precautions make wealthy customers uncomfortable. Within the perfumed interior were three customers, all Russian-speaking women. A salesman, named Martin, showed me diamond-solitaire necklaces in the hundred-thousand-dollar range, which, he noted, might make a thoughtful present for my wife. He told me that he had been with Graff since 1973 and had been in the store the day after Vujosevic canvassed it. Around noon, Vujosevic and an accomplice walked in the door and, in less than three minutes, made off with more than thirty million dollars’ worth of diamonds. It was the biggest jewel heist in British history. “We are delighted to serve the whole world,” Martin told me, dryly. “We would just prefer that people pay for what they like.”

According to British police records, Vujosevic, who had been living in Paris, arrived in London two weeks before the robbery, staying at a cheap hotel in Bayswater, near Hyde Park. His travel arrangements had been made by Milan Jovetic, who was from Cetinje, the former royal capital of Montenegro. A week before the heist, Nebojsa Denic—a hulking Serb from Kosovo, who worked cleaning floors in a Swiss hospital—flew in from Zurich. The three men reportedly met up in Isleworth, in west London, and bought a used Vespa Piaggio motor scooter. It was to be Vujosevic’s escape vehicle.

On the day of the heist, Denic, posing as a customer, entered the Graff store wearing a suit and carrying an umbrella. An Elvis-style pompadour wig sat awkwardly on his head, but it did not alarm the clerks, who thought that he was a rock star in disguise or a wealthy man suffering from a disease. Denic asked to examine a twelve-carat diamond ring priced at four hundred and fifty thousand dollars. “It’s too glamorous,” he said, upon inspecting it. “Do you have a smaller one?”

Denic then pulled out a chrome-plated .357 Magnum, yelling, “Everyone on the floor!” Vujosevic, who had just entered the store, smashed open several display cases with a hammer, pulled out a bag, and scooped up forty-seven pieces of diamond jewelry. Both men ran out the door. A security guard pursued Denic, and tried to wrestle away his gun. It went off, and a bullet ricocheted off an air-conditioner, grazing the nose of a woman walking by.

Steve Alexander, a Scotland Yard detective, arrived to find Denic lying subdued on the ground. Alexander, recalling the incident, said that Denic “was very smartly dressed, but with a ridiculous wig. It looked like a cat was lying on his head.”

Scotland Yard launched an investigation. Within days, detectives in London, who often rely on informants, had identified Milan Jovetic, the Montenegrin fixer, as an accomplice. Jovetic and his girlfriend, Ana Stankovic, were renting a flat in Bayswater, and British police tapped their phones, eventually obtaining a warrant to enter their home. During the search, a detective found a jar of face cream in the bathroom. He stuck his finger in the cream, swirling it around until he felt something hard—a blue-diamond ring, from Graff, worth seven hundred and fifty thousand dollars. (Stankovic had hoped to set the blue diamond in her engagement ring.) After this discovery reached the press, the Daily Mail and other London newspapers dubbed the robbers the Pink Panthers, for one of the Peter Sellers comedies, in which a similar dodge is used.

Scouring the apartment, the police also found two fake Italian passports, with no names or photographs inside. Italy, Alexander explained, is “the route that you take from Montenegro, if you want your movements to be covert.” Alexander was one of several European detectives who told me that the Panthers maintained logistical bases in Italy. Many detectives said that the Italian police had largely failed to coöperate with their investigations.

Jovetic’s phone records led Scotland Yard to an apartment in Paris, which local police identified as Vujosevic’s home, but he wasn’t there. Alexander went to Paris to visit the Brigade for the Repression of Banditry, a special police unit that investigates organized crime. Comparing notes, Alexander and Paris detectives concluded that well-dressed criminals with strong Eastern European accents had pulled off some twenty robberies similar to the Graff heist. French police evidence, including footage from security cameras, indicated that Vujosevic had gone on a crime spree across Europe, robbing Castiglione in Paris, a Graff store in Amsterdam, Wempe in Frankfurt, and jewellers in Geneva and Barcelona.

After months of searching, police intercepted Vujosevic as he was driving into France from Italy. A loaded gun was found in his car. Detective Alexander returned to Paris to interrogate his suspect. He described Vujosevic as “a little bloke . . . the kind of guy you wouldn’t notice twice in the street,” adding that “he was very polite, very articulate.” Vujosevic, however, refused to speak about the Graff robbery, the intended destination of the stolen jewels, his criminal history, his upbringing in Montenegro, or anything else that could have helped the police. After months of investigating, detectives were no closer to understanding who had commissioned the robberies, or where the diamonds had gone.

The London robbery was soon followed by dozens of other Pink Panther heists, in Europe and in Asia; the take from these robberies approached a quarter of a billion dollars. In March, 2004, Panthers targeted a jewelry store in Tokyo. Two Serbs, wearing wigs, entered the store and immobilized a clerk with pepper spray. They made off with a necklace containing a hundred-and-twenty-five-carat diamond. That same year, in Paris, Panthers exploited a visit to Chopard by the wife of Prime Minister Jean-Pierre Raffarin, and stole fourteen million dollars’ worth of jewels from an unguarded display case. In 2005, a Panther team, dressed in flower-print shirts, raided Julian, a jewelry store in Saint-Tropez. The heist, which took place in broad daylight, lasted just minutes. The thieves ran out of the store and down to the harbor, where they escaped in a waiting speedboat.