In the wake of the massive protests over Ferguson police officer Darren Wilson’s killing of Michael Brown, body cameras are, all of a sudden, the en vogue solution for misconduct and civil rights violations by local law enforcement. But will body-cams actually work? It may depend on how much you trust the cops operating them, and whether those writing the rules can untangle the attendant web of privacy, technology and duplicity to make them work.

Despite long-time opposition from some police forces, it now seems the mini-cameras, which can be attached to police officers’ lapel or glasses to record interactions with citizens, cannot be implemented fast enough. A company donated body-cams to Ferguson’s police force, which, under nationwide scrutiny, promptly started using them this week. Soon, cops in Washington DC, Chicago, Los Angeles and New York will all be experimenting with body cameras – if they’re not already.

If used right, this simple technology could represent a huge win for both citizens and the police, as Denver’s police chief Robert White explained when announcing that 800 of his officers would soon be wearing cameras:

The cameras, which will record audio and video, not only will protect people who make legitimate complaints, authorities say, but the technology also should protect police from false allegations of excessive force. ... Citizens should know officers are being held accountable. ... The only officers who would have a problem with body cameras are bad officers.

The most well-known study of the practice backs up this theory about body-cams: they stop bad cops. In Rialto, California, the police force wore the cameras for one year starting in February 2012, and as the Guardian reported, “public complaints against officers plunged 88% compared with the previous 12 months. Officers’ use of force fell by 60%.”

On the face of it, cameras documenting police misconduct could potentially prevent tragedies like Brown’s death, if cops are cognizant that someone’s watching the watchers. Unfortunately it’s more complicated than that. The problem is implementing it.

As Sean Bonner wrote and NPR subsequently reported, when the LAPD forced officers to wear voice recorders after the 1991 beating of Rodney King, things didn’t exactly work out as planned.

[M]ysteriously the recorders stopped working and this kept happening until the department was forced to admit that their internal investigations showed that officers were purposefully breaking off the antennas on their recorders to disable them. Perhaps unsurprisingly the majority of the sabotaged recorders were in the Southeast division — a low income, high minority area with a long history of excessive force complaints. One can imagine mandatory body cameras might suffer similar ‘technical problems.’

These “malfunctions” pop up when cops use body-cams, too. The Albuquerque police department, which was excoriated for civil rights violations by the Justice Department earlier this year, conveniently “forgot” to turn on their cameras before killing at least two people. The Albuquerque Journal reported this week that officers were wearing body-cams when they shot a suspect, and that they all magically turned on their cameras ... after the shooting.

It’s not the first time police have failed to produce lapel footage of a deadly shooting.

No footage was recovered from the officer, identified as Jeremy Dear, who police say shot and killed 19-year-old Mary Hawkes in April. A report from the camera’s manufacturer was inconclusive about why, saying the camera could have malfunctioned or the officer could have turned it off.”

Beyond these malicious moves by those operating the cameras, the future of watchdogging the cops involves a delicate balance between transparency and privacy. There’s the worry that police won’t release enough footage, using secrecy to stifle accountability once again. But there’s also the concern that they’ll release too much, exposing innocent people’s private lives in cases that were never supposed to be recorded in the first place.

San Diego has already experimented with wearable cameras, but so far that experiment hasn’t led to a more aware public, according to Atlantic City Lab’s Sara Libby:

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.... 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.

Then there’s the opposite problem. In many run-of-the-mill cases that don’t involve violence perpetrated by the police, such as domestic disturbances where police enter a home, victims may want to be ensured that footage of them will remain private. “Most of the footage should never see the light of day,” explained the ACLU’s Jay Stanley. “There must be very clear enforcement expectations for when police should have the cameras turned on and good policies around when the video is or is not made public.”

The risk of security breaches are real, too, as local police aren’t exactly known for their technical prowess. Security researchers showed last month that a California town’s 70-camera surveillance system was so insecure, anyone could access the footage.

And, of course, there’s the question of what would happen if these body-cams were connected to all the other high-tech surveillance gear that’s flowing into police departments at a record rate. Matt Pearce of the Los Angeles Times, who provided such invaluable reporting from Ferguson, imagines it:

Matt Pearce (@mattdpearce) Has anyone explored the implications of police bodycams in light of the fact that we've spent the past year scrutinizing other surveillance?

Matt Pearce (@mattdpearce) As in, what if we put body cameras on every police officer, and then departments link those cameras up to facial-recognition technology?

Matt Pearce (@mattdpearce) Remember that in Ferguson, there are huge, huge, huge numbers of outstanding warrants. More warrants than residents.

It’s a long list of worries, but they are solvable problems with the right rules. That’s why even the ACLU endorses police using body-cams, as long as there are strict requirements around their use. A recent study by the Justice Department had favorable conclusions about body cameras, and Senator Claire McCaskill endorsed a proposal to withhold federal funding from police forces that don’t use them.

(By the way, while we’re at it, why isn’t anyone calling for the FBI to implement body-cams? A detailed analysis by Charlie Savage at the New York Times showed that FBI agents shot 150 people from 1993-2011; all 150 shooting were found to be “no fault” of the agent.)

But whether those myriad issues are dealt with or not, body-cams are not a cure-all for police malfeasance. There isn’t one. The systematic problems inside police departments run much deeper than a single solution, and the best way to hold cops more accountable is to allow them to be held them more accountable. That may seem like a self-realizing kind of theory, but constitutional law professor Erwin Chemerinsky recently outlined how current laws on the books, coupled with recent Supreme Court rulings, have provided broad immunity to cops and prosecutors in a variety of situations, even where it’s clear that they have violated someone’s constitutional rights.

The Justice Department has now opened up a civil rights investigation into the Ferguson cops and at least 20 other police agencies. That’s definitely a start. But cops who attack citizens deserve an attack of practicality. Until we overhaul how police are trained – as well as the tactics and tools they use – and punish those who violate it, these violent problems will inevitably fester. Until then, the police will still act as if they are above the law.