A fascinating study of security cameras in San Francisco has concluded that any effect on they have on crime is incredibly localized, and they only works on certain kinds of crime — furthermore, the same number of crimes end up getting committed in the long run, just down the street from the cameras. Still, San Francisco Mayor Gavin Newsom vows to continue putting up the little orwellscopes, because they lull people into feeling secure.
Using a complicated method, researchers were able to come up with an average daily crime rate at each location broken out by type of crime and distance from the cameras. They then compared it with the average daily crime rate from the period before the cameras were installed.
They looked at seven types of crime: larcenies, burglaries, motor vehicle theft, assault, robbery, homicide and forcible sex offenses.
The only positive deterrent effect was the reduction of larcenies within 100 feet of the cameras. No other crimes were affected – except for homicides, which had an interesting pattern.
Murders went down within 250 feet of the cameras, but the reduction was completely offset by an increase 250 to 500 feet away, suggesting people moved down the block before killing each other.
(via Schneier)