Body-worn video cameras being issued to frontline police will automatically start recording when an officer draws their gun from its holster, in an Australian-first, WA Commissioner Chris Dawson has revealed.

WA Police are spending about $18 million over the next five years to buy about 4200 cameras and store the recorded vision in a bid to improve evidence gathering, public confidence and accountability of officers and the community.

Officers in the Perth district, the Traffic Enforcement Group and in the Pilbara will be the first to start using the cameras in June, with the remainder rolled out across the State by mid-2021.

Wearing the cameras will be mandatory but they will not record an officer’s entire shift.

Camera Icon Body worn camera stills from a police training exercise. Credit: WA Police

Mr Dawson said officers would be required to activate the cameras when attending incidents including family violence complaints and “physical or hostile” situations and the technology could back-capture about 30 seconds of vision.

He said they would automatically activate as soon as an officer drew their Glock firearm.

“The last thing I want is for officers in a high-stress situation to be worrying about whether their camera is on or off,” he said.

The technology does not extend to automatic recording when officers draw a Taser, despite stun-gun use previously attracting use-of-force complaints, but Mr Dawson hoped they would eventually add that capability.

Camera Icon Body worn camera stills from a police training exercise. Credit: WA Police

He said police also intended to be able eventually to live-stream vision and audio from the cameras to a police operations centre during critical incidents.

Mr Dawson said body-worn cameras were commonly used in Australia and overseas and other police commissioners had told him they often “de-escalated hostile situations”.

Police Minister Michelle Roberts said it was hoped the new technology would help reduce assaults on officers and increase the number of early guilty pleas.

Mr Dawson said he was working with the Director of Public Prosecutions and the courts to enable interviews and statements recorded on the cameras to be used in court, rather than transferring them into written statements.

Officers will not be able to alter or delete recorded vision.

The video will be stored using secure cloud-based technology.

Mrs Roberts said the State Government was backing the camera roll-out through its $1.4 billion community safety funding.

The public can see police using the cameras at today’s Police Expo at Joondalup Police Academy.