Photo: RNZ / Samuel Rillstone
Police say their rapidly rising use of number plate searching technology is mostly because more officers are doing it, and are more aware of being able to use it.
The number of searches by officers on two private companies' automated number plate recognition systems rose from 64,000 in 2020 to almost 700,000 four years later.
A search of any vehicle's number plate can find all records of it caught on CCTV cameras outside shops and public places going back 60 days.
Police did not provide evidence or make any claim that the rising use of the searches had cut crime.
Data shows crime clearance rates steady or in some cases dropping, with victimisation rates and violent crime also steady.
Police told RNZ the big rise in number plate searches was because more officers were allowed to do it - up by 2500 to 8600 officers between 2023 and last year - and more of them were aware of using it.
"These authorised staff have requested ANPR data in a larger number of cases."
It was "likely" officers were using it more often to investigate high-volume crime.
Data shows burglaries are high volume, but the clearance rate for them has dropped. Many more people were being discharged without conviction in the latest figures than they were a decade ago, which coincides with the police first arranging with private company Auror to access its number plate technology.
Police said another reason for the rise was the same plate entered in both private software systems will register as two searches.
In the Auror system, 14 percent of searches targeted the same vehicle, and in the SaferCities system, that figure was 20 percent.
This might indicate a wide net is being cast across many vehicle plates being searched.
Police said a factor in the use of SaferCities almost doubling to 450,000 searches in one year, was its network had increased the area it covered.
Police said RNZ should ask SaferCities for further details - but SaferCities told RNZ to ask police.
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