French law enforcement officials are racing against the clock on Oct. 21 to find the thieves who carried out a brazen daytime heist at Paris' Louvre Museum.

On the morning of Oct. 19, the robbers shattered a window and stole eight pieces of "priceless" jewelry from the world’s most-visited museum, before escaping on motorbikes, French Interior Minister Laurent Nuñez said on France Inter radio. The museum shuttered its doors following the robbery and remained closed Oct. 21, as it is every Tuesday.

The jewels are worth an estimated $102.63 million, Paris public prosecutor Laure Beccuau told RTL radio on Oct. 21.

Thieves executing this kind of heist typically dismantle or melt down the easily recognizable stolen goods "as soon as possible, within hours, to cut down on the chances of being caught," said Erin Thompson, a professor of art crime at the John Jay College of Criminal Justice. Doing so inevitably diminishes some of their value, she said, but it also makes it harder to trace the items back to the museum.

A specialized police unit known as the BRB, which has dealt with other high-profile robberies, is handling the investigation.

Former police officer Pascal Szkudlara, who served in the unit, told Reuters the investigators will analyze video footage, telephone records and forensic evidence.

"They can have teams working on it 24/7 and for a long period," Szkudlara said, expressing "100%" confidence the thieves would be caught.

Meanwhile, France has ordered a security review at the Louvre, which welcomed 8.7 million visitors in 2024, and pledged to strengthen security measures at the country's other cultural institutions. Justice Minister Gerard Darmanin acknowledged to France Inter radio that officials "failed" to keep the "priceless" jewels safe.

"For too long we have looked into the security of visitors but not the security of art works," Culture Minister Rachida Dati told M6TV.

What will the thieves do with treasures?

In recent years, museum thieves have been moving away from stealing art for its cultural value, instead opting for smash and grab thefts of valuable items that can be easily broken down, Remigiusz Plath, the secretary of the International Counsel of Museum Security, told CNN.

"What we’ve definitely seen in the last five to seven years is some more shift towards raw materials theft," he told the outlet.

If the thieves who hit the Louvre are skilled, they are likely planning to recut the larger gems, said Thompson.

"There's a lot of value in the history, but again, you're going to get easily caught if you try and sell something like a crown of the Empress Eugénie versus a handful of diamonds," Thompson said.

There are a limited number of people with the necessary skills that are willing to take that risk, she said, so the gems could be recovered if something goes awry. But if the process is successful, the gems can be sold "pretty easily" and may never been seen again, even if the thieves themselves are arrested, Thompson said.

"The recovery of objects that are stolen for their material value is very rare," Thompson said.

How the Louvre heist unfolded

At about 9:30 a.m. local time, the robbers allegedly used a crane positioned on a truck to gain access to the Galerie d'Apollon, a first-floor wing of the museum that houses the French Crown Jewels. They broke a window using an angle grinder, smashed two display cases and fled on motorbikes, according to Nuñez.

Prosecutors say the robbery took between six and seven minutes, and the robbers were unarmed but threatened guards with the angle grinders. Investigators believe three to four experienced thieves were involved.

What was stolen from the Louvre?

The eight pieces taken from the gallery include a tiara, as well as earrings and a necklace from a sapphire jewelry set owned by Queen Marie-Amélie and Queen Hortense, the stepdaughter of Napoleon I.

An emerald necklace and a pair of earrings from the Marie-Louise set, the reliquary brooch, along with a tiara and brooch of Empress Eugénie, the wife of Napoleon III, were also taken.

The burglars also allegedly attempted to take a diamond and emerald-covered gold crown owned by Empress Eugénie, but dropped it. The crown, which was damaged in the heist, was found on the ground outside the museum, Paris Prosecutor Laure Beccuau said.

"Beyond their market value, these items have inestimable heritage and historical value," the Louvre said in a statement.

This story has been updated to add new information.

Contributing: Reuters

This article originally appeared on USA TODAY: Where are the jewels? Stolen Louvre loot worth $102 million may be melted down.

Reporting by N'dea Yancey-Bragg and Karissa Waddick, USA TODAY / USA TODAY

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