D.C. Forging Surveillance Network

"There's no way you could have someone watching 1,500 cameras, even with video analytics, and identify crimes," he said.

The D.C. police usually assign two or three people to watch their cameras.

There is broad variation among video systems being developed in U.S. cities. New York, for example, envisions a mix of public and private cameras in its downtown system, linked to pivoting gates that could close off all or part of the financial district to block a suspicious car. Chicago's system is focused on responding to emergencies, rather than routine monitoring, according to a spokeswoman.

The D.C. system is going ahead although it is not yet fully funded. The city has in hand $500,000 of the $9.6 million in homeland security grants it plans to use for the new network, Darnell said. He said that will be enough to get the project started, and the city is confident of receiving the other grants in coming months. They will be used for computer hardware, software and training.

The city will also kick in $886,000 a year, Darnell said.

In its start-up phase, the system will include the public schools, the D.C. Housing Authority, the Office of Property Management and the Transportation Department. By year's end, it will expand to homeland security and the departments of Parks and Recreation, Corrections, Health and Fire and Emergency Medical Services. The schools have the largest number of cameras, about 3,600.

Workers will be cross-trained in the first 60 days to monitor various agencies' cameras at the centralized office in Southeast Washington, Darnell said.

D.C. Police Chief Cathy L. Lanier said this year that violent crime had decreased 19 percent near each of the police crime cameras, which were installed starting in August 2006. Critics have said the cameras simply displace crime to other streets, and they question the cost-effectiveness of monitoring them.

Staff writer Lena H. Sun and staff researcher Meg Smith contributed to this report.