UK court determines police use of live facial recognition legal

Live facial recognition can be deployed nationwide, a U.K. court ruled Tuesday, dismissing arguments from plaintiffs who said the technology is racially biased and is used arbitrarily.

The cameras are typically placed in high-traffic areas and are used to match pictures of passersby to a watchlist of criminal suspects.

London’s Metropolitan Police celebrated the decision, saying the technology has helped them secure 2,100 arrests — including of 100 sex offenders — since 2024. 

One of the plaintiffs, Shaun Thompson, said he was wrongly identified by the cameras and improperly threatened with arrest. The other, Silkie Carlo, is a privacy advocate with Big Brother Watch, an organization that fights against surveillance technologies.

Thompson was threatened with arrest in February 2024 near London Bridge after he was mistakenly identified as his brother, who is on a police watchlist, according to a media summary provided by the court. He refused to provide police with fingerprints to prove his identity.

The episode left him “distressed, angry, and fearful of being wrongly identified again,” according to the media summary.

Thompson and Carlo did not argue that live facial recognition is illegal in principle, but instead contended that the Metropolitan Police’s policy leaves “too much discretion to police officers as to where, why and against whom LFR may be used” and thereby violates European human rights law.

The decision comes at a time when the U.K. has been roiled by debate about law enforcement’s use of facial recognition technology.

In December, the British Home Office said it wanted law enforcement to use facial recognition at “significantly greater scale.” It launched a public consultation to determine how to implement a more robust legal framework for its deployment.

Hours after the announcement, the Home Office released a report from the National Physical Laboratory saying that testing found that facial recognition technology used by law enforcement was “more likely to incorrectly include some demographic groups in its search results.”

The judges in the case decided Tuesday rejected that contention.

“We heard no developed or meaningful challenge on discrimination grounds,” the opinion said. “We are not able to accept, on the thin submissions advanced before us, that concerns about discrimination infect the legality of the policy.”

The Metropolitan Police’s policy only allows live facial recognition to be used in crime hotspots, for “protective security operations,” including at major events and in cases where police have specific intelligence indicating that a suspect is likely to appear in a particular area, according to the media summary.

The court found that the specific use cases along with detailed prescriptions for how watchlists are built and the fact that senior officials oversee the deployment make the technology’s use legal.

In addition to the 2,100 arrests, the Metropolitan Police said in a press release that live facial recognition has led to charges or “cautions” for 1,400 people.

They also asserted that 80% of Londoners favor the use of the technology. 

The National Physical Laboratory found that at the “thresholds” they work at, the system is “accurate and balanced with regard to ethnicity and gender,” the police added.

“This legal judgment is a significant and important victory for public safety,” Mark Rowley, commissioner of the Metropolitan Police, said in a statement. “Live facial recognition works and is one of the biggest breakthroughs for policing.”

Rowley said the cameras captured more than 3 million faces in 2025 and triggered only 12 false alerts. No one who was misidentified was arrested, Rowley said. 

The cameras have led to arrests for suspects in rape, domestic abuse and child sex offense cases, according to Rowley.

The police delete all images of faces that do not match suspects on the police watchlist immediately, according to the media summary. Rowley also emphasized that trained operators examine alerts before police take action.