At the heart of the Michael Brown shooting in Ferguson, Missouri, is a case of he said-he said. Police say Brown reached for an officer's weapon; witnesses say Brown had his hands up in surrender.

It’s no wonder many observers believe the way to prevent future cases like this one is to outfit all police officers with body cameras. That way, there's a neutral record filled with the crucial details that can easily vanish from a person's memory in a crisis or with the passing of time.

Reihan Salam, writing in Slate, touted the many benefits of police body cameras, and pointed out: "Our capacity to remember past events is notoriously faulty. There is a universal human tendency to fixate on some things while neglecting others. Video recordings can help correct for these deficiencies."

The only problem: Even if the officer who shot Brown was wearing a body camera, the footage wouldn't necessarily clear up any of the questions the public—or even the victims and their families—have about how things unfolded, at least not right away. And maybe not ever.

Here in San Diego, our scandal-plagued police department has begun outfitting some officers with body cameras, and the City Council has approved a plan to roll out hundreds more.

San Diego police effectively lock any relevant videos in a vault and throw away the public's key.

Officers wearing the cameras were present during at least two shootings earlier this year. Yet we're still not any closer to knowing what happened in those chaotic moments—whether the perpetrators can be easily identified, what kind of interactions the officers had with those present, nothing.

That's because the department claims the footage, which is captured by devices financed by city taxpayers and worn by officers on the public payroll, aren't public records. Our newsroom's request for footage from the shootings under the California Public Records Act was denied.

Once footage becomes part of an investigation, the department says it doesn't have to release them. SDPD also said during the pilot phase of the camera program that it doesn't even have to release footage from the cameras after an investigation wraps.

I called the department Friday to see whether it's updated any policies surrounding the cameras now that more are being doled out and the program is kicking into full swing.

"We have had very positive feedback from the officers who are using them in the field" but "there are no policy changes to the releasing of evidence from body cameras," SDPD spokesman Kevin Mayer tells me in an email.

Of course, police departments that adopt body cameras could choose to be more forthcoming. In fact, the cameras' value hinges on how a department establishes rules for their use.

"Department rules must establish circumstances under which cops are required to activate the cameras, when supervisors should review tapes, protocol for discipline if/when misconduct is identified, and so on," Joshua Chanin, a San Diego State professor who has studied transparency measures in police departments across the country, tells me. "There are enough instances of cameras 'not working,' footage having gone missing, cops 'forgetting' to turn them on, etc., that rules in place to punish officers who tamper with cameras, erase video are perhaps the most important part of the equation."

None of this is to say that outfitting officers with cameras isn't a worthy effort—the very existence of the cameras can cause police and those they come in contact with to behave more cautiously, and they've been shown to virtuallygrind complaints about bad police behavior to a halt.

"I don't think (cameras) are a silver bullet, but they can be helpful, both instrumentally and in terms of public perception," says Chanin.

But while the cameras help the public by deterring officer misconduct, they're still largely tools for the departments that use them. San Diego police effectively lock any relevant videos in a vault and throw away the public's key. The footage their officers record will never show up on YouTube and go viral. Nor will it help fill in the gaps when a major crime leaves lots of unanswered questions. Crime victims or their families may never get to see and hear what the devices recorded.

Bottom line: The cameras offer plenty of value. But they don't necessarily do what you'd be forgiven for believing was their fundamental job: giving the public a record of what happened.

If you want to make sure the world will be able to see footage of a cop or a criminal caught in the act, you're better off taking the video yourself.