A tiny recording device weighing a few ounces, small enough to fit inside a lapel or within eyewear, may become a police officer’s best protection.

Support appears to be building within law enforcement and among police watchdogs that body cameras, long dismissed due to concerns over cost and implementation, could prevent the kind of civil unrest seen recently in Ferguson, Mo, following the shooting of an unarmed black teen by a white police officer.

Locally, few metro Atlanta police departments are using the cameras beyond a limited or trial basis. Statewide, officers with the Georgia Department of Natural Resources now wear them, along with a handful of local agencies.

But that could soon change.

Cobb County police recently purchased 40 body cameras fir its officers and Atlanta police began testing the equipment on a limited basis within the last two months. So far, the results have been promising, police say.

Complaints about excessive force are down, said APD spokesman Carlos Campos. And officers are spending less time testifying in court, as the introduction of incontrovertible visual evidence has increased plea deals, he said.

“It protects officers from witnesses who many not be truthful and [the public] from officers who don’t do the right thing,” Campos said. The cameras are being worn by select patrol officers, including those stationed at Hartsfield-Jackson International Airport and along the Beltline.

The conclusions, while preliminary, mirror those found in Cambridge University's Rialto Study, the first real gamechanger in the debate over police body cams.

Two years ago, the Rialto, California Police Department placed the body cameras on half its force. The department reported an 88 percent decrease in the number of complaints against officers from the year before. Meanwhile, the “use of force” by officers declined by 59 percent.

The study generated little attention outside of law enforcement circles until last month’s shooting of an unarmed black man by a white police officer in suburban St. Louis. Witness accounts vary as to whether the victim, Michael Brown, was standing with his hands up or moving towards the Ferguson police officer before being shot multiple times. Body camera advocates argue that the technology would have answered the questions that linger about the shooting.

The Ferguson Police Department has already begun training its officers to use body cameras recently donated by a Missouri manufacturer.

“We’re getting interest from departments who didn’t even know about the technology as well as from ones who turned us down just two years ago,” said Steve Tuttle, a spokesman for Taser, one of the leading vendors of body cameras. Eighty percent of Taser’s overall body camera sales have occurred within the last year, Tuttle said.

Public support for the technology is also on the rise. A petition on the White House website calling for all state, county and local police departments to wear body cameras has attracted nearly 152,000 signatures as of Friday. Meanwhile, one Congressman is urging the U.S. Justice Department to fund the purchase of such equipment, which has thus far proven too expensive for most law enforcement agencies.

“It is cost prohibitive for Gwinnett County police at this time,” said Cpl. Jake Smith, a department spokesman. “[We] do not have dash cameras, except for the DUI unit, for the same reason.”

But increased competition is bringing the cost down. The body cameras used in the Rialto Study cost $900 apiece though estimates for the equipment now range between $300 and $400 per camera. The equipment used by the APD sells for $399, Campos said.

However, there are additional costs.

Marietta police recently looked into purchasing body cameras but declined, said Ofc. David Baldwin, noting concerns over the expenses attached to storing the video footage on the city’s computer server.

Attempting to address those concerns, the two largest vendors for body cameras are now offering cloud-based storage systems for a monthly subscription fee.

Meanwhile, advocates say the cameras pay for themselves, pointing to a study by the Washington, D.C. Police Complaints Board that found the cameras reduce the number of costly lawsuits brought against the police force.

While historically there has been pushback from some law enforcement groups, calling the cameras an “encumbrance,” the head of the Atlanta Police Union said he’s heard little negative feedback from his officers.

“If everyone else is recording we might as well do it too,” said Ken Allen, president of the International Brotherhood of Police Officers Local 623. “Law enforcement needs to keep up with the new technology. Those that are old school, like me, are going to have to adopt.”

“They are more benefit than hindrance,” said Allen, though he stressed protocols still need to be adopted that address privacy concerns for both citizens and officers.

Campos said while there’s been no final decision on using body cameras permanently, the APD “thinks this is the direction to go.”

“We think there’s a lot of potential here,” he said. “Cameras don’t lie.”