After resisting for decades, Major League Baseball has adopted instant replay on nearly all disputed calls, providing a transparent and public view of what happened. While this frustrates many by slowing down the action, it almost always gets the call right.

Michael Brown's shooting death by Ferguson, Missouri, police has made a national issue out of the lack of "instant replay" for altercations between cops and citizens. At least one witness claims Brown stood with his hands up and screamed "I don't have a gun, stop shooting!" while a "source close to the department's top brass" told FoxNews.com that Brown nearly beat Officer Darren Wilson unconscious before Wilson shot Brown six times.

With such disparity between eyewitness accounts, and with high-definition video technology so inexpensive and ubiquitous, there is a growing demand for police to record their interactions with the public. As Reason's Ron Bailey wrote, "Requiring law enforcement to wear video cameras will protect your constitutional rights and improve policing."

There have already been some ups and downs with experiments in police cameras. Cameras have been turned off, failed to record, and footage has been lost. It will also likely take some time before departments require their officers to record and preserve video evidence rather than merely suggesting they do so.

Still, in places like Rialto, California, the mere presence of cameras has resulted in a precipitous drop in complaints and use of force. It has also improved community relations with the police, since everyone tends to exhibit more civilized behavior when they know they are being recorded.

In The Guardian, Rory Carroll writes:

"Rialto's randomised controlled study has seized attention because it offers scientific – and encouraging – findings: after cameras were introduced in February 2012, public complaints against officers plunged 88% compared with the previous 12 months. Officers' use of force fell by 60%. "When you know you're being watched you behave a little better. That's just human nature," said Farrar. "As an officer you act a bit more professional, follow the rules a bit better." Video clips provided by the department showed dramatic chases on foot – you can hear the officer panting – and by car that ended with arrests, and without injury. Complaints often stemmed not from operational issues but "officers' mouths", said the chief. "With a camera they are more conscious of how they speak and how they treat people." The same applied to the public; once informed they were being filmed, even drunk or agitated people tended to become more polite, Farrar said. Those who lodged frivolous or bogus complaints about officers tended to retract them when shown video of the incidents. "It's like, 'Oh, I hadn't seen it that way.'"

Which brings us to the disappointing news coming out of San Diego, where the police department asserts the evidence captured by police cameras is not for public consumption. As reported by Sara Libby in City Lab:

(The San Diego Police 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.

Got that? You, the taxpayer, pay for the cameras and the salaries of the people wearing the cameras who are charged with protecting and serving the community, but you are not entitled to review the footage of controversial police encounters, including shootings. Not even when the case is closed.

Such a policy makes the use of police-worn cameras beneficial only to police and not to the public. For a "scandal-plagued" PD like San Diego's, it's not surprising that they would prefer to set the precedent of one-way transparency, but it's unlikely to satisfy the public that justice was done.

If the public and the press do not get to vet the video evidence, they will remain dissatisfied with the government's assertion that they got the call right.