Two Security Camera Studies
From San Francisco:
San Francisco’s Community Safety Camera Program was launched in late 2005 with the dual goals of fighting crime and providing police investigators with a retroactive investigatory tool. The program placed more than 70 non-monitored cameras in mainly high-crime areas throughout the city. This report released today (January 9, 2009) consists of a multi-disciplinary collaboration examining the program’s technical aspects, management and goals, and policy components, as well as a quasi-experimental statistical evaluation of crime reports in order to provide a comprehensive evaluation of the program’s effectiveness. The results find that while the program did result in a 20% reduction in property crime within the view of the cameras, other forms of crime were not affected, including violent crime, one of the primary targets of the program.
From the UK:
The first study of its kind into the effectiveness of surveillance cameras revealed that almost every Scotland Yard murder inquiry uses their footage as evidence.
In 90 murder cases over a one year period, CCTV was used in 86 investigations, and senior officers said it helped to solve 65 cases by capturing the murder itself on film, or tracking the movements of the suspects before or after an attack.
In a third of the cases a good quality still image was taken from the footage from which witnesses identified the killer.
My own writing on security cameras is here. The question isn’t whether they’re useful or not, but whether their benefits are worth the costs.
Clive Robinson • January 13, 2009 8:01 AM
Hmm,
“quasi-experimental statistical evaluation… …the program did result in a 20% reduction in property crime within the view of the cameras”
What about property crime outside of the view of the cameras?
Did it go down up or stayed the same proportionate to the general trend of adjacent areas without CCTV coverage.
There have been findings in the UK that although there are short term gains in the covered area for aprehension and conviction in the long term rate tends to be slightly worse than befor.
Various reasons have been fielded primarily that the criminals either take precautions to hid their identity or they move to adjacent areas. And it has been sugested that a combination of both has actually made the figures worse than would otherwise be the case.
The problem is that these things are very difficult to assess in a truly independent and statisticaly sound way.
What the first study does show (and is confirmed by many UK findings) is that “spur of the moment” crime (usually violent) is unchanged by CCTV.
And to be quite honest what would I rather see a reduction in “property crime” or “violent crime” in it’s various forms.