Minneapolis police officers must turn on their body cameras when responding to any call, traffic stop, or self-initiated activity, Acting Police Chief Medaria Arradondo announced Wednesday, in a key change to city policy in the wake of Justine Damond's shooting death.

"What good is a camera if it is not being used when it may be needed the most?" Arradondo said at a Wednesday news conference, where he and Mayor Betsy Hodges acknowledged some officers have not been using their cameras enough.

In the eight months the equipment has been in use, officers have been allowed broad discretion on when to turn on the cameras, reports the Minneapolis Star Tribune.

The new policy, effective Saturday, will require officers to turn on the cameras in any encounter with the public, heeding an until-now disregarded 2015 recommendation from the Police Conduct Oversight Commission that police officer discretion on use of the cameras be all but eliminated.

Within about two months, police officials said, the cameras will activate automatically whenever an officer activates his or her squad car's lights. Installation of that technology is underway, taking about two hours per squad car. The Minneapolis Police Department has about 200 squad cars.