Body cameras are key for police accountability. We can’t let them erode privacy rights. (Washington Post)

The national movement toward body-worn cameras has been driven by tragedies over the past several years in which civilians — frequently black men and boys such as Eric Garner in Staten Island, N.Y., Walter Scott in South Carolina, and 12-year-old Tamir Rice in Cleveland — have died at the hands of police officers. Killings that, at an earlier time, would have likely disappeared in the fog of police obfuscation have exploded into national controversies for the simple reason that they were caught on video.

Video’s power to improve policing lies in the fact it makes us all eyewitness to police-civilian interactions, ranging from tragic shootings to more quotidian but nonetheless disturbing stop-and-frisks, which are common and, as a federal judge in New York found in 2013, often unconstitutional. Video provides compelling evidence of police misconduct and can be used to train, discipline, fire and even prosecute officers. It’s also a potent tool for exonerating officers falsely accused of misconduct. Ultimately, the aim is avoiding illegal, inappropriate police-civilian interactions, because everyone involved acts differently knowing a camera is rolling.

But the efficacy of this technology depends on how it’s used, and the NYPD’s recently released body-camera policy illustrates just how important it is to get the details right, starting with the on/off button. Because some of the things that take place during an officer’s shift shouldn’t be recorded (such as conversations with confidential informants, undercover officers or child victims), body-camera programs rely on officers to turn the cameras on and off at the appropriate times. This means body-camera rules must properly specify which incidents are to be recorded, and departments must be vigilant in assuring that officers don’t manipulate cameras to avoid recording misconduct.

The NYPD’s program illustrates how these initiatives can run into trouble. Importantly, rather than requiring officers to turn on the camera whenever an officer seeks to question a civilian, as advocates had demanded, the NYPD policy requires recording only when the interaction rises to the person being searched, arrested or “suspected of criminal activity.” As a result, many low-level investigative encounters that can quickly escalate in circumstances where turning the camera on may not be safe or feasible will not be recorded. Moreover, the policy has precious few details about supervisory review, and doesn’t include language about consequences of noncompliance, simply noting in an accompanying report that officers face “possible discipline after the conclusion of a 90-day period of field training” if they fail to adhere to departmental guidelines.

Another accountability flaw with the NYPD program is that it virtually eliminates the public as eyewitness. To get access to NYPD videos, the public and press must file open-records requests, to which the department can take months just to respond, with actual production often taking far longer. By contrast, the Seattle Police Department, after blurring body-cam footage to protect the identities of individuals depicted, posts its videos on YouTube. For police body-camera programs to succeed as accountability reforms, the videos cannot be secrets hidden inside police departments.

Compounding this problem is the fact that officers can get quick access to most videos, which gives them the ability to build a one-sided public-relations narrative, while victims of misconduct are left with only their own accounts as evidence. In other words, the NYPD policy further stacks the deck against victims.

But making body-worn police cameras better accountability tools is only half the challenge, when one realizes that New York City soon will have 20,000 police officers wearing cameras pointed at the public all day, every day. Before long, the NYPD and other police departments around the country will have a huge cache of footage of people in all walks of life, with citizens in black and Latino communities particularly likely to be recorded on video, given the concentration of policing in their neighborhoods. With facial recognition software already used by the NYPD to match images to its mug shot database, it’s only a matter of time before that technology is used in concert with body-worn camera systems. One need not indulge in Orwellian fantasies to recognize that body-camera programs threaten to become powerful tools of mass surveillance by the police.

To balance citizen protection with citizen privacy, the NYPD program needs these safeguards: First, all body-camera footage should be stored with and controlled by an agency independent of the police, with strict rules governing access to the footage. While any government possession of the footage poses privacy risks, we are most concerned about mass-surveillance video archives in the hands of law enforcement.

Next, recording must be strictly limited, with express prohibitions on filming lawful civilian behavior, including political and religious activity, if that behavior doesn’t implicate a law enforcement necessity. To assure these restrictions are honored, body-camera recordings should be reviewed by authorities outside the police department, with systems in place to immediately halt improper videotaping.

Finally, other than situations in which video will be used to resolve a complaint, in a criminal prosecution or in a disciplinary proceeding, videos should be destroyed as quickly as possible (recognizing that videos that are altered so individuals cannot be identified may remain in the public realm). After all, the best way to minimize abuse is to minimize the size of archives.

Now is the time to make sure body-worn cameras become tools of reform, not mass surveillance. With modest but critical improvements, the NYPD’s program can become a national model.