Woolworths is rolling out body cameras at all its 191 stores this week, as part of staff safety measures.
The supermarket chain trialled the cameras in 17 stores and said staff felt safer and reported the cameras helped de-escalate conflict and abuse from customers.
Physical assaults more than tripled in the last six years from about 60 in the 2018 financial year to about 230 in 2024, Woolworths said.
Thefts also tripled from about 5500 to 15,000 in the same period.
Meanwhile, there were eight times more security incidents in the same period going up from about 100 to 780.
Woolworths NZ's head of health safety and wellbeing Denva Wren said there has also been a rise in the number of verbal threats.
"These range from threats to injure, threats to come back after the store is closed, threats to kill. It's really awful and unaccaptable."
The cameras were worn round the neck and aimed to be a deterrent to conflict, she said.
"Actually when members of the public or offenders are having conversations with our team and understand these may actually be turned on, we see the de-escalation occurring and they're only really being used in a small number of events," she said.
"Footage will not be released except when requested by police as part of an investigation."
Retail New Zealand's chief executive backed Carolyn Young backed the move.
"If something is a good deterrent and it's been proved to be effective against aggressive customers, then we'd really support that because it has been really difficult in retail recently."
Body cameras were used successfully in other sectors such as the fisheries sector, she said.
Privacy Commissioner Michael Webster said the body cameras were similar to CCTV.
"The rollout of these cameras is somewhat similar to the use of closed circuit TV by a number of retail stores.
"[Woolworths] have got a number of rules around how it's going to be used."
He said its use was not as intrusive as facial recognition technology, which is being trialled by supermarket rival Foodstuffs.
Earlier this month, a customer was mistakenly identified as a trespassed "thief" at a New World in Rotorua through the Foodstuffs' facial recognition technology trial.
"Facial recognition technology, because it captures a digital image of our most personal information is a much more privacy intrusive form of technology than simply recording through a body cam," Webster said.
The commissioner said he expected retailers to use a range of methods to increase security, not to just rely on technology.
The rollout is part of Woolworths' three year, $45 million programme to add more security measures to stores.
Other measures include walkie talkies and trolley lock systems.
"Every security measure implemented in Woolworths stores complies with New Zealand law including privacy requirements," Woolworths New Zealand director of stores Jason Stockhill said.