In this era of video documenting nearly every moment of public life — and a lot of private moments, too — people have felt less than satisfied with taking official assertions on faith.

Perhaps this applies no more readily than to a community’s police force. In particular, in cities where there have been controversies over police-involved killings or other violent encounters with the public, the public has wanted its own documentation of events. Often it’s supplied in the form of cell-phone videos that may show events in conflict with the account presented by police officers.

Many police departments have implemented body cameras worn by officers; the recordings they produce can protect both the public and law enforcement from unfair accusations.

This week the Honolulu Police Department has joined other law enforcement agencies, including those in the other three Hawaii counties, in using the body-worn cameras. The test is a 30-day pilot project, involving the Body 2 camera manufactured by Axon. The devices are being tried on 77 officers during night-watch hours, when varied police calls come in.

The project got an encouraging endorsement from HPD’s newly installed Chief Susan Ballard. Its implementation at last, delayed due to technical issues concerning the storage of the video data, should be lauded, though the systems aren’t without challenges and limitations.

That’s because the public trust in police across the country has taken a blow in recent years, owing to several controversies such as the shooting of civilians in their encounters with law enforcement. Most infamously this was exemplified by the police killing in Ferguson, Mo., but there have been other mainland trouble spots, too.

Fortunately, Hawaii communities have not suffered anything like that kind of disconnect between neighbors and their police officers. But residents here also deserve far greater openness about how the police interacts with the public.

The program would ease concerns, especially in Honolulu. This city has been rocked the last few years by turmoil over the former police chief, Louis Kealoha, and corruption allegations made against him and his wife, Deputy Prosecutor Katherine Kealoha, and four other police officers.

Adoption of these cameras has been a national trend, but in some cities, the costs of managing the new video databases have driven officials to abandon it. One reason: Other states’ lawmakers have increased minimum periods for storage of the videos, and the police departments deemed the associated costs too heavy to bear.

That’s something that Hawaii’s Legislature, as well as the city officials overseeing HPD budget requests, should probe carefully.

State Sen. Will Espero, one of the lawmakers who introduced bills to set parameters for the body cam programs, said projections for storage costs should be laid out clearly. Protocols must be developed for retaining enough data that have a practical purpose, and for making it as accessible as any public record.

In some cities, a solution known as software-defined storage has been adopted, an approach that contains costs by reducing the needed proprietary hardware for the system. Such innovations must be explored here as well.

“At the end of the day, I believe it will be a benefit, protecting the officers who serve and protecting the public from abusive behavior,” Espero said, and he’s undoubtedly right.

This is not a panacea for community-police flash points, which will still persist. The most recent studies show body cams to have a somewhat mixed record in deterring bad behavior. And the video record may not always yield precisely the evidence that would be helpful to a case.

But with the public needing some reassurance about police practices, Honolulu should welcome this new element of transparency at HPD.