France's police striving to identify and arrest looters who shattered shops in last weekend's unrest are relying on one tool to trigger their forensic follow-up: social media.
"We are working the social networks... then we go over all that with our own tools, to see if the crimes seen on social media correspond with the crimes we're studying," said an officer seated in a special operations room with 10 screens in front of him.
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The officer, identified only by his first name, Bruno, was seated in a gamer-style chair, pushing a mouse around as looked closely at a video.
He said he was convinced he had identified a group of four youths who took part in the looting that had scarred Paris streets.
Using street security cameras as well as cameras installed in the Paris region's transport system, Bruno tracked the four as they carried their haul, almost up to their home addresses.
The officer was one of a dozen specialists carrying out similar digital hunts on screens in the cramped Security Operational Coordination Centre.
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Footage and police footwork
The team, at work since Monday, has 80,000 security cameras at its disposal, whose images it can tap into.
Images on TikTok, Instagram, Discord and other social media platforms often provide the first clues.
"Maybe a victim talks about a crime but doesn't go to the police station to report it – they're in shock, they wonder whether it's worth going – but they post it on social media," Bruno said.
"And so from that, we start checks, see about the geolocation... See if we can find the victim and if we can find the crime. If we find the crime, we send that to the criminal investigation unit, which takes over."
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At that point, footage and footwork combine to potentially build a case.
A suspect identified "might say 'no, that's not me', but if we see their face in a video..." another officer in the unit said, implying that images were persuasive evidence.
"It's not the only tool to close a case, but it's one of the very useful tools for investigators," she said.
The process has already been used in other protest-related cases recently, such as in the assault of a trainee police officer in eastern Paris, or when a group of youths threw bricks from a chimney at police in the city.
To help the video sleuths, Michel Lavaud, a security official for the greater Paris region, told his team that a platform had been set up for witnesses to crimes committed in the street during the unrest to upload images they recorded.
200 investigators
Justice Minister Gérald Darmanin has also announced that facial recognition would be used to compare a police database of mugshots with images posted on social media.
The French government, under fire for not having done enough to stop the violence, is underlining its determination to catch perpetrators of the riots and looting.
Prime Minister Sébastien Lecornu has ordered more than 200 investigators to work on that.
A specialised national detection unit has been set up, pooling transport security services with the police unit that battles organised crime.
It was scrutinising "all leads but also the available images, from security cameras, cameras in stores and videos on social media", the Paris police prefecture told AFP.
"Our deployment relies on three complementary pillars: dissuasion, through our presence in the streets; stopping crimes in the act; and prosecuting the crimes," the city's police chief, Patrice Faure, said.
Suspected looter nabbed
The painstaking screen-watching and detective work has not been needed in all cases.
In the southern town of Vienne, near Lyon, a 19-year-old man was arrested Sunday when he walked by the police station, masked and carrying bags of stolen clothes, shoes and jewellery.
Police said the man tried to run when he was spotted by officers walking out of the station, but was swiftly nabbed by other officers nearby.
"He admitted stealing some of the items from a store and said he found a bag full of items in the street that he picked up," the prosecutor's office in Vienne told AFP. It estimated the value of the looted items at €4,500 ($5,000).
(FRANCE 24 with AFP)