Police in Ferguson, Mo., are now wearing body cameras, and reports suggest that interest in the technology among police departments nationwide has spiked since unrest swept the St. Louis suburb last month.

The shooting death of unarmed black teen Michael Brown by a Ferguson police officer on Aug. 9, as well as the sometimes-violent protests that followed, raised deep questions about race and justice in America. Protesters point to a culture that they say devalues the lives of black youth, making white cops less hesitant to pull the trigger. Defenders of police officers say they do their best in threatening situations fraught with uncertainty.

The lack of facts in the Ferguson case has so far offered few answers between these two views, leading to simmering distrust. The same dynamic has played out in the Trayvon Martin case, as well as many others, where use of lethal force against black youths has been justified as self-defense – but doubts have remained, especially among the black community.

The spike of police interest in wearable cameras, however, suggests Ferguson is prompting many police departments to take steps toward addressing this problem. The motives are not yet clear and are likely varied: Are the cameras seen primarily as a public-relations effort to deflect growing public pressure or as an honest effort to address the trust gap that exists between police departments and aggrieved residents?

Nationwide, the trend toward wearable cameras is only in its infancy and shows both the promise of the technology and its shortcomings. Data suggest complaints and violent encounters can decline significantly, but police can also maintain a "blue wall of silence" to prevent public access to the videos. The cameras can be very useful in improving policing, experts say, but should not be viewed as a cure-all.

"These cameras are viewed as the ultimate silver bullet, but they're not," Barry Donelan, president of the Oakland Police Officers' Association, told the San Francisco Chronicle. "They're another great tool in policing, but they have limitations just like everything else."

Ferguson police began wearing the cameras, which in general can fit on a lapel or on eyeglasses, on Saturday, Police Chief Tom Jackson told the St. Louis Post-Dispatch. Since riots erupted in Ferguson after Mr. Brown's death, companies selling wearable cameras have noted a significant uptick in interest.

"We have had a lot more enquiries because of the civil unrest that is going on over in Ferguson," Stanton Ross, chief executive of camera-maker Digital Ally, told Reuters.

Currently, about 1,000 of the 18,000 police departments nationwide are using wearable cameras, according to an MSNBC report. But for many activists and Ferguson protesters, the hope is that wearable cameras will become part of a broader recalibration of American policing, post-Ferguson.

"People here are asking if the incident could be a seminal moment, not just in North St. Louis County but across the USA, in how police departments relate to and serve black communities," writes reporter Rick Jervis of USA Today in a first-person essay about his time covering the Ferguson protests. "Calls for police wearing mobile cameras and diversifying ranks are gaining momentum."

The experience from Rialto, Calif., encourages that hope. Rialto is the first police department in the country to outfit all its officers with wearable cameras, according to a CBS News report. As a result, the number of complaints of excessive force against the department in this Southern California Inland Empire city of 100,000 dropped from 24 in 2012 to three in 2013.

"People tend to behave a little better when they know they're on camera," Police Chief Tony Farrar told CBS.

Cost is one issue for cash-strapped cities. But critics note that even with video, underlying issues don't go away. The beating of black motorist Rodney King by white cops, after all, was caught on video, yet a jury that included no African-Americans acquitted the officers – a verdict that was viewed as so unjust that it sparked riots in Los Angeles in 1992.

Moreover, wearable-camera technology is subject to abuse. A body camera worn by a member of the Albuquerque Police Department recorded a video of police shooting and killing a homeless man in the back. But a Justice Department investigation of the incident revealed that "officers failed to record some incidents even when it was the officers themselves who initiated the contact, making their failure to switch on their cameras or recorders before beginning the encounter especially troubling."

Police videos can also be kept confidential. Sara Libby of The Atlantic's "City Lab" writes of San Diego's experiment with wearable cameras:

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.

The limitations and problems involved with deploying wearable cameras don't outweigh the benefits, experts say. But they need to be taken into account, or deeper police reforms will be cast off as "solved" by technology.

"Given the role of police in maintaining public order, it may never be possible to eliminate tragedies resulting from police-citizen confrontations," writes Michael Dorf, a professor at Cornell School of Law, on the Justia website. "Outfitting police with wearable cameras would be a very useful first step in reducing the likelihood of such tragedies. It should not, however, be the only step."