CHICAGO -- A car circles a high-rise three times. Someone leaves a backpack in a park.
Such things go unnoticed in big cities every day. But that could change in Chicago with a new video surveillance system that would recognize such anomalies and alert authorities to take a closer look.
On Thursday, the city and IBM Corp. are announcing the initial phase of what officials say could be the most advanced video security network in any U.S. city.
"Chicago is really light years ahead of any metropolitan area in the U.S. now," said Sam Docknevich, who heads video-surveillance consulting for IBM.
Chicago already has thousands of security cameras in use by businesses and police - including some equipped with devices that recognize the sound of a gunshot, turn the cameras toward the source and place a 911 call. But the new system would let cameras analyze images in real time 24 hours a day.
"You're talking about creating (something) that knows no fatigue, no boredom and is absolutely focused," said Kevin Smith, spokesman for the city's Office of Emergency Management and Communications.
For example, the system could be programmed to alert the city's emergency center whenever a camera spots a vehicle matching the description of one being sought by authorities.
The system could be programmed to recognize license plates. It could alert emergency officials if the same car or truck circles the Sears Tower three times or if nobody picks up a backpack in Grant Park for, say, 30 seconds.
IBM says this approach might be more effective than relying on a bleary-eyed employee to monitor video screens. "Studies have shown people fall asleep," Docknevich said.
It is unclear when the system will be fully operational. Existing cameras could be equipped with the new software, but additional cameras probably will be added as well, Smith said.
"The complexity of the software is going to define how quickly we are able to do this," he said.
Chicago's announcement comes as it is vying to bring the 2016 games to town. A purportedly security-enhancing surveillance system is something city officials could trumpet to International Olympic Committee.
"The eventual goal is to have elaborate video surveillance well in advance of the 2016 Olympics," said Bo Larsson, CEO of Firetide Inc., the company providing the wireless connectivity for the project.
Neither Smith nor IBM would reveal the cost of the network, but Smith said much of it would be paid by the Department of Homeland Security. The cost of previous surveillance efforts has run into the millions of dollars. Just adding devices that allow surveillance cameras to turn toward the sound of gunfire was as much as $10,000 (?7,052) per unit.
Some critics question whether such systems are effective and whether they could lead to an unwarranted invasion of privacy.
Jonathan Schachter, a public policy lecturer at Northwestern University, said there are no studies that show cameras reduce crime. And the idea that placing cameras near "strategic assets" would prevent a terrorist attack is "absurd," he said.
Ed Yohnka, spokesman for the American Civil Liberties Union of Illinois, said he was concerned that more cameras and more sophisticated technology would lead to abuses of authority.
"It is incumbent on the city to ensure that there are practices and procedures in place to sort of watch the watchers," he said.