Foodstuffs South Island is trialling facial recognition in three Pak'nSave supermarkets in Christchurch Photo: 123RF
A report into facial recognition systems used on shoppers shows teenagers are the worst offenders for threatening supermarket staff.
Foodstuffs South Island is trialling facial recognition in three Pak'nSave supermarkets in Christchurch.
Its Privacy Impact Assessment said it would not be used on vulnerable people or minors under age 18.
However, the report also said that across its South Island network of stores, six out of 10 of the top offenders were under 18.
"While six out of the top 10 offenders are minors across the FSSI store network, no minors or vulnerable people will be included in the watchlist during the project," said the 26-page report recently made public.
RNZ asked what percentage of serious threatening behaviour incidents were being committed by minors at its supermarkets, but the company did not say.
Foodstuffs SI had justified the move into facial recognition in part by pointing to an "escalating level of serious threatening behaviours by repeat offenders in FSSI supermarkets [that] poses a significant risk to the health and safety of staff and customers in-store".
The company said the preponderance of teenagers among offenders did not undermine its expectation that adult-only facial recognition was a good way of combating the issue.
"Excluding minors does not reduce the usefulness of the trial," said a spokesperson.
"Its purpose is to assess whether facial recognition technology can help our teams identify adult repeat offenders who have previously been involved in serious incidents, so they can step in early to prevent further harm. The trial is also helping us understand the operational impacts and processes involved with using facial recognition in our stores."
It had identified 206 repeat offenders at 38 stores in 32 suburbs in the last year involved in over a thousand events, the privacy assessment said.
"We're seeing increasing levels of serious, threatening and violent behaviour in our stores from repeat offenders across all different age groups."
Camera on continuous record
The three-month trial began in October at its Pak'nSave stores in Redwood and Sydenham, and its New World St Martins.
The software integrates with a camera that is continuously recording images.
In an earlier trial in some North Island Foodstuffs stores, the system scanned 226 million faces to raise 1742 alerts, with 1200 of those confirmed on watchlists.
A watchlist only had on it people who had previously been violent, threatening or aggressive in their stores - and were then categorised in one of two ways: 'Extreme Threat' and 'High Risk'. A match with someone's template had to be 92.5 percent accurate for it to be flagged at which point two trained store members would check it and decide what to do next, said Foodstuffs South Island.
"This may include observing the person, contacting Police, or intervening to ask them to leave the FR Store - if it is safe to do so," said the chain's website.
Facial recognition was a proportionate response because North Island supermarket trial had been effective at reducing serious threatening behaviour, the privacy assessment said.
The North Island trial was assessed by the Office of the Privacy Commissioner that concluded, "While the level of privacy intrusion was high because every visitor's face is collected, the privacy safeguards in the trial reduced it to an acceptable level."
The tech must only be used with robust processes including human checks, it said.
"FRT systems have potential safety benefits, but they also raise significant privacy concerns."
A template of every shopper
The privacy assessment for the current South Island trial showed Foodstuffs was using IT systems from an Australian firm, Vix Vizion, which scored highly for accurate facial recognition in 2022, and Auckland company Auror.
Auror is a big player in vehicle licence plate recognition but earlier said it had avoided facial recognition till a few months ago because the technology had not been accurate enough at the time.
Its product, Subject Recognition, had a module and person of interest lists that could not be accessed by police, whereas police access its licence plate system hundreds of times a day.
Like Subject Recognition which Auror has begun offering stores, Foodstuffs' trial runs on a system that created a temporary biometric template of every shopper at the three test stores, then dumped it if there was no match to a watchlist, the privacy assessment showed.
A detection was stored within the Auror platform for seven years, though the image itself would be deleted the same day, said the assessment.
"All personal information collected and stored within the FRT System, including the watchlist, is stored in Microsoft Azure Australia (by Auror Limited within the Auror Platform) and Amazon Web Services (AWS) NZ/Australia" by Foodstuffs.
The company said before starting the trial it engaged with the Office of the Privacy Commissioner, or OPC. The OPC would be getting "high level" monthly updates.
Facial recognition relies on biometrics, like a person's face or fingerprints.
The office's biometric processing privacy code came into force on 3 November so does not apply to the supermarket trial.
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