Here are the latest statistics on crime in Britain. Police statistics, according to this BBC report, show that violent crimes have gone up, while another survey shows that violent crimes are broadly stable. (The usual health warnings about statistics obviously apply). However you look at it, crime is high.
Regardless of what one thinks about the potentially civil libertarian worries about millions of CCTV cameras now scattered around the country, it hardly appears that they are very useful in deterring crime, which as far as I know, was the stated purpose for the things.