From the outside, what unfolded at the Louvre on Sunday appeared akin to an athletic feat. In a swift seven minutes, a band of thieves scaled a furniture elevator, broke through a gallery window, ground through display cases and rode off in broad daylight on motorbikes with a heap of French crown jewels.

But to Robert Wittman, the former senior investigator and founder of the FBI’s National Art Crime Team, “the real art in an art heist isn’t the stealing, it’s the selling,” he told The Washington Post.

“These types of things are so well-known that it’s almost impossible to walk into anywhere and just try to off-load,” he said of the purloined items, which include headpieces, necklaces and earrings worn by French royalty.

Wherever the thieves are, they’re probably not resting on their jewels just yet, art crime experts told The Post. Their work has only just begun.

What happens to an object after it’s swiped from a museum depends on the nature of the item, and frankly, whether the thieves care about history and art - a scenario some say is unlikely, despite the art-appreciating bandits of Hollywood.

Stolen paintings have to remain intact since a bit of paint and canvas have little value unless they add up to, say, a recognizable Picasso or Leonardo. But jewelry, such as the nine pieces taken from the Louvre (one of which was recovered because the burglars dropped it), presents more opportunities for thieves because the gems can be cut into smaller pieces, and metals can be melted down, allowing each object to essentially be sold for parts.

Many experts believe that by now, the pieces, which include thousands of diamonds and other jewels, have already been dismantled.

But Wittman was hopeful that the thieves could be preserving the trove in hopes that the French government might offer a reward. “One is a terrible tragedy,” he said of breaking down the gems. “The other is something that happens quite often.”

“Even criminals … know the value in them is their uniqueness in that they are historical and they have heritage,” he added.

That doesn’t mean the items are getting first-class treatment, though.

“They’re probably in a sack in somebody’s bedroom,” he said, pointing to a case he investigated in Madrid in which $50 million worth of paintings were stashed behind a refrigerator.

Leila Amineddoleh, an adjunct law professor at Fordham University whose practice includes art and cultural heritage, was less optimistic. “They absolutely do not care about these jewels,” she said. “I doubt any of the thieves were like, ‘Hmm, let me steal this for my wife or girlfriend, this is going to look beautiful on her.’”

“No one can wear that tiara in public,” she said.

Amineddoleh said there’s a small possibility that the thieves had a buyer lined up to purchase, say, the tiara whole, but “most likely it’s being dismantled.”

Owned by the likes of Empress Marie Louise, second wife of Napoleon Bonaparte, and other royals, the jewels could have been worn at a coronation or at meetings with dignitaries, Amineddoleh said. If they have been taken apart, what’s lost is “that historic heritage value, and that’s irreplaceable,” she said.

When items are targeted for material value, said Erin Thompson, an art crime professor at John Jay College of Criminal Justice, “they are transformed as quickly as possible to decrease the risk of detection.”

Precious metals might be melted down, as may have happened with the 18-karat golden toilet stolen from Blenheim Palace in 2019. Yogi Berra’s World Series rings, which were swiped in 2014, were melted in a garage.

Jewels, which need to be cut, present an added layer of logistics. The thieves have to find “a crooked lapidary,” Thompson said, who will recut the stones to make them unrecognizable.

“If you’re really organized, maybe you line that up in advance,” she said. “If you’re not so organized, maybe you are now frantically Googling.”

Usually, those behind a burglary will ensure the object leaves the perpetrators’ hands, so they aren’t caught with them. This can present obstacles, too. In 2012, thieves in Britain left stolen Chinese antiquities at a previously agreed-upon site - but couldn’t locate them later. The prosecutor described the case as a “steal it, can’t find it” failure.

If the thieves do go on to sell the goods, a payday can quickly turn sour. More difficult are artworks, whose worth is tied to their recognizability; such paintings are estimated to sell on the black market for just 7 to 10 percent of their potential open-market value, according to the FBI. And some painting snatchers have walked into their own trap trying to get cash for their loot.

Vincenzo Peruggia, for example, stole the Mona Lisa from the Louvre in 1911 and sat with it for two years - during which time he claimed to fall in love with her - only to get caught trying to ransom it to an art dealer in Italy. The men behind the 1994 theft of a version of Edvard Munch’s “The Scream” met a similar fate when a police officer posed as an art dealer claiming the Getty Museum would pay them to return the painting.

With jewels and metals, the difference between their value as raw materials and as historical objects is huge, Thompson said, but they’re still “worth a pretty penny.”

When it comes to jewels, “it’s a legal market that has gray edges,” she said, pointing to pledges jewelers make to not work with conflict diamonds through what’s called a Kimberley certificate - documents, she says, that are often faked.

“You don’t make money as a jewelry dealer by saying no when people come to you with good deals,” she added.

Tim Carpenter, who worked on art crime at the FBI for 17 years, including as head of the Art Crime Team, said there’s a good chance the jewels have crossed international borders and expects that the thieves have go-to buyers.

“Like any other commodity, you’ve got really ethical dealers, and then you’ve got some that aren’t quite so ethical,” he said. “That’s what these organized crime groups rely on.”

It’s unlikely the gems will be returned in full, experts says. In similar situations, such as the 2019 theft of jewels from a museum in Dresden, Germany, the pieces have been only partially recovered. But if they do, they’re likely to see even more attention: The saga of the Mona Lisa’s theft is often credited with making her an icon.

In recent years, Carpenter says he’s seen a “shift in tactics” where crime groups have started targeting art less and turning to precious metals, gold and jewelry instead, since it has a separate market value by weight.

But Carpenter bristles at questions about how much the jewels are worth.

“As cultural heritage items, they’re priceless,” he said. “... Until you can figure out how to rewind the clock a few hundred years, meet the artists that created these jewels in the first place and have them remade - they’re priceless.”