It is perhaps a case of once bitten, twice shy for Police as it resumes using facial recognition technology in investigations.

This time around it will be strictly by the book – that book being the Police Use of Facial Recognition Technology (FRT) – Police Manual chapter.

In 2020, a small workgroup in Police conducted a short FRT trial using technology from Clearview AI. However, RNZ revealed Police did not have the necessary clearance from the government or the Privacy Commissioner to tutū with the software. The trial was quickly shut down.

Nearly five years later, Police is taking a much more considered and controlled approach. It has established a specialised facial recognition (FR) team within National Forensic Services to assist with serious criminal cases. The four-person unit has been operational since June and is the only authorised group within Police to use the strictly regulated technology, which has been available since 2022.

“We’re very aware that this is a controversial area,” Police Technology Assurance adviser Dr Andrew Chen said during a recent webinar about the current state of FRT in Aotearoa. “The overriding principle for us is maintaining public trust and policing by consent.”

Privacy, legal, security and ethics issues informed the new FRT policy, which clearly points to New Zealand’s cautious attitude. It puts strict parameters around the who, what, when, where and how.

Most notably, the FR team will only use the technology retrospectively in active investigations and only if specific criteria are met. All FR requests need to be approved by the submitting member’s supervisor before they are submitted for FR analysis, and results inform an investigation, they are not used as evidence.

“We’re not going out fishing, or just hoping we find something useful,” Andrew said, adding that FRT is employed with a strict human-in-the-loop approach. “It’s all about improving efficiency and accuracy for humans, not replacing them.”

Tech writer/researcher James Sweetland believes FR will grow significantly in the coming decade. He recently interviewed 34 FRT experts for a Policing Insight project called Facing the future: the rise of FR in policing.

He found a striking variety in Western countries’ approaches to FR – the most ambitious being England and Wales’ growing use of live FR (surveillance), which he believes is “justified and proportionate” but not without issues.

He is not surprised by New Zealand’s approach.

“If there’s limited social licence, then notusing it is a sensible decision. It’s a valuabletool, but one that remains controversial andis best applied where public trust won’t beundermined by its use... yet, as FR becomesmore common in Western policing, perhapsthat public trust calculation will change.”

Layers of checks

Back in Aotearoa, Police is content to keep it simple and defined for now.

National Forensic Services capability manager Detective Inspector Craig Mason has overseen the FR unit becoming operational. Supervisor Jess Vaughan leads the team, which is part of the Image Management Unit (IMU) based within the National Biometrics Information Office. A conscious decision was made to base the FR team at PNHQ. Police says it is not looking at making the technology available in the districts.

The FR team’s initial focus has been on serious crimes, critical incidents and sexual offences, although it has also assisted with some drug-related investigations. As of September 19, there have been 98 FR searches covering offences including murder, aggravated robbery, wounding with intent and sexual offending.

Craig says the FR team takes a two-step approach: “Images of unknown suspects are run against an algorithm via lawfully held photographs including prisoner, returning offender, child sex offender and firearms licence photographs. The algorithm does not search against passport photographs or driver licences photos.

“That provides us a list of candidates. From that, we introduce the human factor. Our people conduct a morphological analysis of the face and produce a comparison report. Only trained employees are authorised to undertake FR comparisons. These then undergo a peer review process from a second trained face examiner and are then approved by the IMU supervisor before being released back to the investigation team.

“It is important that the FR team has highquality images to work with, compressed files that have been saved over and over may be problematic, but the team will still try. A great option for the FR team is having the ability to review video footage so they can select the most suitable image for comparison.”

Feedback from investigators has been positive, Craig says. “Previous to FR, an officer would need to post a message on Pānui or include the unknown image as part of a ‘Famous Faces’ slide and wait for a nomination. With FR, they can usually have the request completed within a day or two.”

Runs on the board

National Forensic Services manager Detective Inspector Sonya Douglas says transparency and monitoring are key to ensuring the use of FR succeeds in Aotearoa.

“Everything’s upfront. [The FRT policy] has everything in it that anyone would need to know around how it’s actually being applied. There's nothing sensational about what we're doing.

“We’re updated virtually on a daily basis on how the team's going. There are also scheduled quarterly governance reviews to ensure we remain within policy. This also means we’re not trying to ‘back capture’ once we realise 12 months has gone by, and perhaps there could have been enhancements made.”

The desire is to build a strong track record before expanding the FR team’s services, Sonya says.

“We would like to get some really good runs on the board with serious crime, and really promote the value of the team. With increased requests, the FR team members will build on their capability and experience, and their turnaround times are expected to improve as they build their expertise. As the capability grows, they will be able to widen the scope of requests to include other offending.”

NZ Police is also part of the Australasian face special advisory group, or FaceSAG, governed by the Australia New Zealand Policing Advisory Agency.

“Our training and career structure is closely aligned with our Australian counterparts, and we have regular meetings. Police is also quite aware of what other countries are doing,” Sonya says.

Andrew says police use of FRT is spreading globally, often provoking controversy.

“The jurisdictions that appear to be most innovative tend to have higher crime rates and a very different law enforcement profile [to New Zealand].”

He cited an example of a United States expert who said they were surprised by New Zealand’s approach to FRT because there, if something is not illegal, they'll do it. Whereas New Zealand can spend months or even years ensuring that their actions will stand up to any legal challenges.