UK police deploy facial recognition at London’s Notting Hill Carnival

London’s Metropolitan Police deployed live facial recognition at this year’s Notting Hill Carnival. The technology, which has been used by U.K. police 111 times this year, has stirred debate over privacy and public safety among civil liberties groups and law enforcement.

The annual carnival, which celebrates Caribbean culture, attracts around 2 million attendees and is considered Europe’s largest street party. In a statement to X on Tuesday, the Metropolitan Police defended the technology’s use as “successful” after identifying “almost 100 people of interest” on Sunday and Monday.

‘Almost 100 people of interest’

“Live facial recognition proved to be a successful part of the Notting Hill Carnival policing operation,” the police force wrote. “The technology helped officers identify almost 100 people of interest over two days who, without it, would likely have been able to go unnoticed in the busy crowds.”

As of Monday evening, 423 arrests had been made, according to police. The most common arrests were for cannabis possession, possession of an offensive weapon and drug supply. Other arrests stemmed from sexual offenses, robberies and two stabbings. Of those arrests, 52 came after individuals were identified by the department’s live facial recognition system.

‘Mass surveillance tool’

In a letter sent to Metropolitan Police Commissioner Sir Mark Rowley prior to the carnival, 11 civil liberties and anti-racism organizations described the technology as “a mass surveillance tool that treats all Carnival-goers as potential suspects.”

“Notting Hill Carnival is an event that specifically celebrates the British African Caribbean community, yet the [Metropolitan Police] is choosing to use a technology with a well-documented history of inaccurate outcomes and racial bias,” the letter said.

The letter cites an ongoing judicial review brought by a 39-year-old Black London resident who says he was wrongly identified by the system in February 2024 and detained by police.

The Police Commissioner has previously denied claims that the current algorithm used by his department’s system “exhibits bias.”

The Minderoo Centre for Technology and Democracy reported in 2022 that British police use of facial recognition technology violated both human rights laws and ethical norms.

The deployment this year marked the third time the technology had been used at the carnival. Although facial recognition was deployed in 2016 and 2017, widespread pushback led police to temporarily discontinue its use.

“We acknowledge that when LFR was previously deployed at Notting Hill Carnival in 2016 and 2017, it did not build public confidence,” the commissioner said. “At that time, the technology was in its early stages and the algorithm’s performance was limited. The legal and oversight position was also very different.”