Scottish police maintain nearly no knowledge on facial recognition use

It’s not attainable to evaluate the reliability, efficacy and equity of Police Scotland’s retrospective facial recognition (RFR) use as a result of the drive doesn’t conduct any audits or efficiency assessments, says Scottish biometrics commissioner Brian Plastow.

Whereas reside facial recognition (LFR) makes use of cameras to scan public areas and crowds to establish folks in actual time by matching their faces towards a database of photos compiled by police, RFR might be utilized to any already-captured photos retroactively.

Not like LFR, which is used overtly with specifically outfitted cameras atop a visibly marked police van, police RFR use is rather more covert, and might be utilized to footage or photos behind closed doorways with none public data the surveillance has taken place.

Whereas Police Scotland recurrently makes use of RFR search capabilities, it’s but to deploy LFR.

In keeping with a joint assurance evaluation revealed by Plastow and His Majesty’s Inspectorate of Constabulary in Scotland on 25 March 2025, Police Scotland “doesn’t at present gather, retailer, or analyse particular knowledge to evaluate the effectiveness” of its RFR know-how, and holds “terribly little knowledge” on the system’s general efficiency. 

For instance, the evaluation famous there isn’t any data on what number of RFR identifications led to profitable outcomes, equivalent to arrests or resolved instances, or how correct the know-how is.

This contains no data on the speed of false positives and negatives, within the absence of which, “it’s not attainable to evaluate the reliability, effectiveness, and equity” of the system, the evaluation said.

With the data obtainable, the evaluation discovered that between April 2023 and March 2024, Police Scotland carried out 3,813 RFR searches of the UK’s Police Nationwide Database (PND), and 193 searches by way of the Youngster Abuse Picture Database (CAID). Nevertheless, throughout each databases, a possible match was present in simply 2% of instances.

For comparability, the Metropolitan Police carried out 31,078 searches by way of the PND over the identical interval, whereas Larger Manchester Police carried out 5,290, though the evaluation didn’t include data on what proportion of those forces’ searches resulted in a match.

The evaluation additionally discovered that whereas Police Scotland’s common use of the PND is audited, the drive conducts no audits of its RFR use and has performed no post-implementation evaluation of its effectiveness.

Together with the entire lack of analysis, the evaluation highlighted that Police Scotland nonetheless doesn’t have a transparent roadmap setting out its long-term imaginative and prescient or technique for utilizing biometric applied sciences.

“Not conducting analysis, and never having a method makes it troublesome for Police Scotland to know which applied sciences it ought to use (or not use) and which it ought to spend money on (or not spend money on),” it stated. “The absence of any revealed analysis makes it troublesome for the general public to know whether or not these are efficient policing instruments.”

Police Scotland is at present aiming to have a biometrics coverage in place by the top of October 2025.

The evaluation additionally recognized points across the high quality of custody picture pictures, the poor decision of which makes them unsuitable to be used in facial recognition searches.

“A sizeable portion of custody photos aren’t searchable beneath PND facial search performance,” it said. “This hole might imply that individuals who have had their custody picture beforehand taken aren’t being detected on future probe photos uploaded by Police Scotland, which might result in crimes not being detected.”

Police Scotland stated a “software program concern” was inflicting the custody photos to be captured at a lower-than-recommended minimal dimension, which, together with additional compression, is making them unusable.

“Excessive warning have to be exercised with any retrospective ICT repair to uncompress these photos. In the event that they can’t be totally restored to their authentic format, the reliability of the information may very well be considerably compromised,” stated Plastow. 

“Police Scotland ought to guarantee this concern is solved, notably contemplating the adoption of recent methods such because the UK Dwelling Workplace Strategic Facial Matching Undertaking.”

To alleviate the problems recognized, the evaluation made 4 suggestions to Police Scotland concerning its use of RFR.  

This contains creating a bespoke coverage on the usage of RFR to look PND and CAID; conducting a coaching wants evaluation for all officers and workers recurrently working on this space; and enhancing the gathering of knowledge evaluating the effectiveness of Police Scotland’s RFR know-how.

It additional beneficial that the drive improves the decision of its custody photos earlier than collaborating within the Dwelling Workplace’s Strategic Facial Matching Undertaking.

“In an more and more digital world, the way forward for regulation enforcement lies in attaining the best stability between the introduction of recent applied sciences for public security and safeguarding elementary rights,” stated Plastow.

“For biometrics, public confidence ought to be maintained with transparency, strong governance and impartial oversight. This, together with the problems highlighted in our report, ought to immediate vital reflection for policing in Scotland.”

Responding to the findings of the evaluation, assistant chief constable Steve Johnson stated: “We’ll take into account the Scottish biometrics commissioner’s suggestions in full, and within the context of the event of our biometrics technique, coverage and normal working procedures. 

“Our Biometrics Oversight Board is already conscious of this concern and is overseeing work to enhance the standard of photos taken in custody and the collaboration with the Dwelling Workplace Strategic Facial Matching Undertaking, which mirrors the suggestions.”

The evaluation additionally highlighted ongoing points across the unlawful retention of tens of millions of custody photos within the PND, that are nonetheless being held regardless of the Excessive Court docket ruling in 2012 that they have to be deleted.

Whereas Plastow famous within the evaluation that this implies the PND incorporates “a whole lot of 1000’s” of illegally retained custody photos, the earlier biometrics commissioner for England and Wales, Fraser Sampson, estimated in February 2023 that “there are most likely a number of million” unlawfully held photos within the database.

The Nationwide Police Chiefs’ Council (NPCC) beforehand confirmed to Pc Weekly in November 2023 {that a} nationwide programme between policing and the Dwelling Workplace had been launched a month earlier than to make sure consistency and coordination throughout how police retain, course of after which use custody photos, notably for facial recognition functions.

Whereas the joint evaluation acknowledged the existence of this NPCC-led programme, it contained no data on its progress.

Because it stands, there are over 19 million custody photos in PND, 16 million of that are enrolled within the database’s RFR search gallery – though a excessive variety of duplicates means it’s unknown what number of people are included within the knowledge.

Police Scotland’s lack of administration data shouldn’t be restricted to its use of RFR.

In February 2025, a separate evaluation by Plastow into the usage of DNA knowledge by Scottish policing our bodies discovered they’re failing to correctly file and publish knowledge on the ethnicity of arrested folks, that means there isn’t any means of building whether or not minority teams are over-represented in policing databases.

“Throughout our fieldwork, the Scottish Police Authority [SPA] Forensic Providers and Police Scotland have been unable to supply us with any dependable administration data on the ethnicity of anybody held throughout the Scottish DNA Database, because the database is almost 30 years outdated and was not designed to file this data,” stated Plastow on the time.

“The truth that SPA Forensic Providers and Police Scotland are failing to correctly file and publish knowledge on the ethnicity of arrested folks whose biometric knowledge is then held is regarding, towards the context of the previous and present chief constables having said publicly that problems with institutional racism persist inside Police Scotland.

“Accordingly, now we have been unable to ascertain whether or not there’s any over-representation on the grounds of ethnicity or every other protected attribute in Scotland.”