Police kept using facial ID system despite bias data

Police forces successfully lobbied to use a facial recognition system known to be biased against women, young people, and members of ethnic minority groups, after complaining that another version produced fewer potential suspects.

- Mark Wilding Daniel Boffey

UK forces use the Police National Database (PND) to conduct retrospective facial recognition searches, whereby a “probe image” of a suspect is compared to a database of more than 19m custody photos.

The Home Office admitted last week that the technology was biased, after a review by the National Physical Laboratory (NPL) found it misidentified Black and Asian people and women at significantly higher rates than white men, and said it “had acted on the findings”.

Documents seen by the Guardian and Liberty Investigates reveal that the bias has been known about for over a year - and that police forces argued to overturn an initial decision designed to address it.