Updated

The nation's largest police force wants to install hundreds of surveillance cameras in busy commercial districts and other areas where there have been spikes in robberies and burglaries.

Police officers already watch live feeds from surveillance cameras in housing projects throughout the five boroughs, NYPD (search) spokesman Paul Browne said.

The new cameras, however, would not be monitored. Instead, they would record high-quality digital videos that would be reviewed in the event of a crime to look for evidence. Police also believe the cameras would serve as a deterrent.

Civil liberties groups argue the practice does more to encroach on the privacy of average citizens than it does to discourage and catch criminals.

Cameras "are no substitute for cops on the street," said Donna Lieberman, executive director of the New York Civil Liberties Union (search). "That's what we need to reduce crime."

But Browne said law-abiding New Yorkers would have nothing to fear.

"These are locations where there is no expectation of privacy," he said.

The police department is seeking city funds for some 400 new cameras. No detail was provided on a timetable or the cost of the plan.