Live facial recognition cameras have been used at London railway stations 17 times since February. They have yet to identify anybody on a police watchlist.
British Transport Police began the trial at London Bridge on 11 February. Waterloo followed two days later and Euston four days after that.
The equipment subsequently appeared at King's Cross, St Pancras, Liverpool Street and Victoria. It was used four times at Victoria and another four times at King's Cross.
Details of the trial were released by the Department for Transport on 4 August, in answer to a question from Conservative MP Shivani Raja.
One alert was generated during the 17 operations. The passenger was stopped, but turned out not to be the person shown on the watchlist.
The department said the error was "resolved quickly". It gave no further account of the stop.
British Transport Police publicised the trial on its website. Deployment dates were posted online and notices were placed in the stations while the cameras were there. Some of the posters carried QR codes.
BTP said another route would be provided for passengers who preferred not to walk through the camera area. Pictures which failed to produce a match would be deleted at once.
That was the notice given to passengers. They were not approached beforehand or asked for their agreement.
The force has published nothing showing how often people used the other route. It has not reported how many passengers saw the station notices before reaching the cameras.
A person rushing for a train might have read the poster. Another might have walked straight past it. Both could have had their faces checked.
This was more than the usual station CCTV. The police were comparing passengers with photographs of people they wanted to find.
There is a legal peculiarity behind the trial. Parliament has never enacted a law specifically authorising and regulating police facial recognition.
BTP's own policy runs to 46 pages. It draws its authority from common-law policing powers, then lists the Data Protection Act, the Human Rights Act and the Equality Act among the laws which officers must observe.
The Home Office opened a consultation on 4 December 2025. In the document, the government acknowledged that the existing arrangements were hard to understand and did not always give the public confidence in police use of the technology.
Ministers want a new law. They have also proposed putting oversight in the hands of a statutory body.
None of this had been completed when the cameras arrived at London Bridge in February. BTP went ahead under the existing arrangements.
The results published in August are incomplete. They contain the station dates and the outcome of the alerts, but not the number of people checked.
The size of the watchlists is also missing.
Without those two numbers, there is no proper measure of the trial. We do not know whether the cameras compared hundreds, thousands or far more passengers with police photographs.
BTP had called the operations intelligence-led. The stations were chosen because officers believed people wanted for serious crimes might pass through them.
The police returned to King's Cross on 4 March, 2 April and 11 July after the first operation there. They went to Victoria on 9 April, 20 May, 27 June and 2 July. Nothing on the watchlists was found.
The false alert is the sole example of the equipment selecting somebody. The passenger involved has not been identified, and there is no published account from them.
Perhaps the stop lasted only a moment. We cannot tell from the phrase "resolved quickly".
British Transport Police planned to evaluate the pilot once the six months were over. That evaluation should settle some of the missing points, particularly the number of faces checked and the number of photographs searched for at each station.
It may also show whether passengers noticed the warnings and what BTP made of the one incorrect alert.
For the moment, the known facts are fairly spare. Police took facial recognition equipment to seven London stations on 17 occasions. No wanted person was identified. One passenger was stopped by mistake.