The Ineffectiveness of Security Cameras
Data from San Francisco:
Researchers examined data from the San Francisco Police Department detailing the 59,706 crimes committed within 1,000 feet of the camera locations between Jan. 1, 2005, and Jan. 28, 2008.
These were the total number of crimes for which police had reports -- regardless of whether the crimes were caught on video. The idea was to look at whether criminals stopped committing crimes at those locations because they knew cameras were there.
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.
The final report is expected to analyze the figures in more depth and to include other crimes, including prostitution and drug offenses.
This quote is instructive:
Mayor Gavin Newsom called the report "conclusively inconclusive" on Thursday but said he still wants to install more cameras around the city because they make residents feel safer.
That's right: the cameras aren't about security, they're about security theater. More comments on the general issue here.
Posted on April 7, 2008 at 1:33 PM • 75 Comments