Retrospective facial recognition searches can still pick up custody photographs that should have been deleted, according to a report by His Majesty’s Inspectorate of Constabulary and Fire and Rescue Services. The watchdog warned that public confidence in law enforcement’s use of the technology could be damaged if custody images are wrongly saved.
Findings on Police Use of the Technology
The report covered the use of retrospective facial recognition by police and the National Crime Agency. It found that oversight was inconsistent, and some junior officers were unaware that matches produced by the software cannot be treated as evidence.
Retrospective facial recognition is most often used to compare images from an investigation, such as CCTV footage, with pictures held on the Police National Database. Investigators are then expected to carry out their own inquiries to corroborate the finding before taking action.
Concerns Over Oversight and Training
“We found that forces didn’t use retrospective facial recognition (RFR) consistently,” the report said. “While experienced investigators generally understood its limitations and the need to corroborate potential matches, less experienced investigators often had a weaker understanding.”
“Some investigators didn’t know that RFR results were intelligence rather than evidence and required further inquiries before officers took enforcement action. This creates a risk that people could be incorrectly identified or arrested, which could undermine public confidence in the technology.”
Inspectors found a small number of cases where officers relied too heavily on the technology, which led to inappropriate investigative action. There were also inconsistencies in oversight of the use of RFR.
Retention of Custody Images
“The retention of custody images remains an area of concern,” the report said. “We found that some images which should have been deleted under existing retention rules remained available for facial recognition searches. This risks undermining public confidence and highlights the importance of ongoing national work to improve compliance, strengthen image management processes and align the treatment of custody images more closely with other biometric data.”
The report found some forces were not complying with national audit requirements. Figures from the National Police Chiefs’ Council showed that two forces in England and Wales had audited the correct number of RFR files, seven forces had not appointed an auditor, and two auditors could not access the police national database. Ten forces had audited more than the 1% of records they are required to examine, and 22 either failed to submit a return or sent in incomplete information.
Recommendations and Next Steps
The report made recommendations including improvements to national and local governance, the introduction of clear national standards, moves to improve oversight and training, and making sure the technology is used more consistently.
“We analysed the available data and found that the public generally supported the police service’s use of RFR. But continued support will depend on maintaining public confidence, openness about its use and effective safeguards.”
Inspectors visited seven police forces – British Transport Police, Metropolitan Police and those in Cheshire, Dorset, Gwent, Northumbria and Surrey – and the National Crime Agency, in March and April this year. Earlier this month, the Home Office pledged to bring in tougher laws around the use of live facial recognition technology by police, where cameras are used to scan every passing face in case of potential matches with a watch list. Laws will be introduced to Parliament under the Police Reform Bill to make sure police use of facial recognition is “intelligence-led and proportionate”, so it is only used when officers believe wanted people could be present in a certain area, the Home Office said.
