KING'S LYNN, England -- Inside the winged, brick police headquarters of this placid Middle England market town, Sgt. Peter Thompson flips on his video recorder to demonstrate a high-technology crime-fighting system that is the stuff of paranoid science fiction -- and, it appears, a model for Britain's future.


On Thompson's black-and-white monitor, a lone woman walks nervously in the town center just before midnight. Two teenagers in leather jackets and Mohawk haircuts stalk her. One of the teens shatters a shop window with his boot, snaps the aerial off a car, dumps over a garbage can, pulls a piece of fried chicken from the refuse and chomps it as the woman looks on in alarm. "That's the quality of yob we've got in this town!" Thompson cackled in disgust as he watched.


But fear not. Suddenly, two policemen rush from out of camera range, intercept the ruffians, wrestle the troublemaker under control and assure the woman she can go safely on her way.


That videotaped arrest is but one of hundreds made since 1992 with the aid of a pervasive video surveillance system that allows King's Lynn police to peer with cameras into the nooks and crannies of their town's public spaces, 24 hours a day, seven days a week, 52 weeks a year.


Besides generating on-the-spot arrests, such pervasive video surveillance has slashed property crime in the town center, saving hundreds of thousands of dollars in insurance losses.


The King's Lynn system is the most advanced example of a trend sweeping Britain. Rattled by rising street crime and unrestrained by a written constitution or an enshrined right to privacy, at least 300 towns and counties around the country have installed or are planning pervasive video surveillance of public spaces to catch and deter criminals, according to Photo-Scan Ltd., a leading installer.


The market for such systems in Britain has quadrupled since 1989 to more than $200 million annually, according to the British Security Industry Association.


Britain's Home Office, which oversees the country's police, is promoting video surveillance as one of the "most exciting and constructive applications of new technology in the fight against crime," as Junior Home Minister David Maclean put it in a recent speech.


Closed-circuit television has long been used in Europe and the United States to monitor such vulnerable crime venues as banks, retail outlets, airports and subway systems. But in Britain the concept has extended to cover entire towns and city centers -- parking lots, streets, high-crime housing projects, industrial areas, sports complexes, churches, graveyards and small alleyways.


But civil libertarians fear that Britain is fulfilling the prophecies of George Orwell's novel "Nineteen Eighty-Four," in which the writer warned against a totalitarian state in which an all-seeing Big Brother keeps an omniscient eye on the citizenry.


With cameras all around, "there is a chilling effect which is quite difficult to put into tangible words or feelings," said Atiya Lockwood of Britain's National Council for Civil Liberties. "On the other hand, you have to balance it out against people feeling more comfortable if they are in an area where they are walking alone."


Of greatest concern, Lockwood said, is the absence of laws to govern the uses of video surveillance. The Home Office says it hopes to publish non-binding guidelines on such issues this fall.


Public surveys in Britain depict ambivalence about the new systems here. A clear majority express support for the widespread use of video cameras to stop crime. But in one detailed survey, four out of 10 said they believe the new cameras will be used "to spy on people."


Promoters of city-wide video surveillance dismiss misgivings about the systems as the products of overactive imaginations. They describe critics as isolated intellectuals who have no feel for the public's determination to fight rising crime.


In many cases, they point out, the surveillance systems here are installed by democratically elected governments that can be replaced by voters if abuses are uncovered or the public grows dissatisfied. "We're not prying into private lives," said Barry Loftus, the King's Lynn surveillance project director. "The majority of people on the street -- we don't know who they are and why they're there. My view is that cameras actually protect civil liberties. They don't erode them (because) we've reclaimed the town center" from criminals.


Yet the King's Lynn experience also suggests that video surveillance has a momentum all its own. Originally, there was no plan for such a large system here -- it just grew and grew as more sections of the town clamored to be included.


The project began with seven fixed cameras in a burglary-plagued industrial park. Then, in 1992, it expanded to 32 cameras to stop crime in parking lots. To protect privacy, at first only stationary cameras were installed near residential areas. But today, this town of 30,000 has 60 cameras linked to its central surveillance command.


Yet King's Lynn doesn't have a serious crime problem in comparison to elsewhere in Britain. Street muggings have always been rare here, murders rarer, and rapes virtually unheard of. "What it comes down to is, there's a perception of crime, a fear of crime, rather than actual crime," Loftus conceded. The surveillance system has grown because of the "feel-good factor" it creates among the public, he said.