London Cameras - No connection between cameras and clear up rate
In 2007 members of the London Assembly obtained information about surveillance cameras in the London boroughs under the Freedom of Information Act. They also obtained crime clear up rates for each of the boroughs. The data shows that CCTV has little effect on solving crime.
These findings are contrary to what Assistant Chief Constable Nick Gargan of Thames Valley Police told the House of Lords Constitution Committee in January 2008. Gargan said:
"The principal measure of effectiveness as far as the Police Service is concerned is in relation to the support of the investigative process. [...] Interestingly, there is very little academic research on the effectiveness and usefulness of CCTV in the investigation of crime, most of it is focused on does it reduce crime, not what is the impact of it in terms of investigating crime."
The statistics show that more CCTV cameras don't lead to a better crime clear-up rate. This is best illustrated when the figures are plotted as a graph (see below) which shows that there is no linear dependence between the number of cameras and percentage of clear-up.
London has over 10,000 state run cameras.
Graph of number of cameras vs. percentage crime clear up rate
(Prepared by No CCTV using the figures obtained by the Greater London Assembly)