The highly-respected Urban Institute in Washington, D.C. has come out with the first comprehensive analysis of the cameras. The group wanted an in depth look at how police use cameras to fight crime in Washington, Baltimore and Chicago. The first two cities remain a work in progress.
For Chicago, the study's architect says, the early results are quite positive.
The POD cameras went up as part of a pilot project seven years ago. Today there are nearly 900 of the cameras on street corners in some of Chicago's higher crime neighborhoods.
"You know what, I think our neighborhood is happy they're here," said Dana Nance, West Humboldt Park resident.
Many who live and work in their shadow love the cameras. Others wonder if they're little more than hi-tech scarecrows.
"There's still activity. There's still stuff happening at night. Who's watching the film?" said Greg Calhoun.
The Urban Institute set out to study the effectiveness of the cameras as a crime-fighting tool. Using a sophisticated model, and three years of data, researchers sought to find - do the cameras lesson crime? Do they just move it? Is there a cost benefit to their use?
"So not just whether the cameras would reduce crime, but whether the reduction was such that it offset the cost of the cameras themselves," said Dr Nancy LaVigne, director, justice policy, Urban Institute.
Dr. Nancy LaVigne led the study which focused on two neighborhoods - Humboldt Park and West Garfield Park. Each has a fairly high concentration of cameras.
In Humboldt, the conclusion is that the cameras have had a real impact. Drug, robbery, weapons offenses, and overall crime dropped significantly after cameras arrived.
The same, however, is not true in West Garfield where there was no signficiant change pre and post camera.
So why would they have an impact in one neighborhood and not in another? There are a number of possible explanations, but the short answer is researchers don't know. What they can say, however, is that if you combine the numbers from the two neighborhoods, the cameras still have a significant impact on crime.
Fewer crimes means you spend less on investigation, less on the court system and less on victims of crime.
"We found that for every dollar spent on cameras, there was over a $2 savings in terms of the money that was averted for the crimes that were prevented," said Dr. LaVigne.
"I think it confirms what we expected to find, and it confirms I think what the public expected," said Commander Jonathan Lewin.
Police say POD cameras citywide last year played a direct or indirect role in nearly 900 arrests. Some of them probably wouldn't have happened without the cameras.
A call about possible gunshots leads on an officer at the 911 center to remotely control a POD camera. Squads are called and several men are arrested with three semi-automatics in the trunk of a car.
One camera records a drive-by shooting. People scatter. No one is hit. There have been no arrests.
Video from another camera led police to witnesses who led police to two men now charged in a gang murder.
In spite of those cases, some in West Garfield Park, for instance, remain unconvinced and believe the cameras do nothing to discourage crime.
"If I was selling drugs right here, I'm gonna do that," said Rudy Jordan.
A perception here is that nobody's really watching, and when there is violent crime within lens range, the panning camera seems to always be looking the other way.
"Our study is interesting because it suggests that cameras can have a very powerful impact on crime and a cost beneficial one, but it also suggests that cameras don't work in all places and all contexts," said Dr. LaVigne.
Defining those places and contexts is the challenge because more cameras are definitely coming.
"I can see a day when they might become as ubiquitous as street lights. There's even some talk about technology to embed the camera in the street light itself. We're not there, but someday we'll see more cameras," said Lewin.That someday is, of course, happening already. Dr. Lavigne suggests, though, that you don't put cameras everywhere just because you can. You put them up where it's prudent and cost beneficial.
The study also found no real evidence that a camera on one block moves crime to another without a camera. Researchers were surprised by that. And finally, for the cameras to have real impact there must be both perception and reality that human beings are routinely watching.