San Bernardino County Sheriff John McMahon said human behavior can change when body cameras are involved.
It's one of the reasons his department has been experimenting with the devices, since as far back as 2009.
"We all act better when we know we're being watched," McMahon said.
Top news of the day
But, he added, "we need to act the right way regardless of whether or not somebody's watching."
McMahon spoke about cameras after his deputies were caught on a NBC4 News helicopter camera beating a man after a horseback pursuit on Thursday.
The outcry over Francis Pusok's beating has exposed the sheriff's department to negative national publicity and potential lawsuits.
"I do believe it will benefit and protect our deputy sheriffs and it will help to disprove any complaints that we may get," McMahon said.
Sheriff's officials said a deputy-involved shooting in San Bernardino County on Wednesday was not recorded on cameras.
The project McMahon announced this week is a pilot program and the most a deputy might carry would be an audio recorder.
Once the body-cam program is implemented, he said, deputies responding to a scene like the one on Wednesday may likely be recording pictures and sound.
The department has the backing of county supervisors and McMahon said a secure "cloud" system will be used to make sure all recordings are kept confidential.
"We wanted to make sure it complies with all state and federal laws," he said.