Actually the bombers in London, the 'Bus Bombers' were caught on these cameras running from the scene PRIOR to the explosion.. and if I remember right the subway attackers in Japan were too.
The London bus bombers were suicide bombers. The ones where the bomb went off were dead.
The Japanese sarin gas attackers were members of a cult that was already under investigation, already been planned for a raid and when they learned of the raid which was about to happen they conducted the attacks as a preemptive move.
They caught two of them because they went straight back to the cult's headquaters. One of them was sick from the sarin which was pretty damning evidence in itself.
They were not caught because of the cameras.
The 9-11 hijackers were all identified on surveillance cameras, and the links made to known terrorists and terrorist cells.
The cameras made the investigation easier, not necessary for an investigation to be successful.
Crimes of terrorism were successfully done long before surrevailance cameras were everywhere.
It's a fact that MOST criminals don't want to be caught, and if they know there is a camera in the vicinity will NOT comitt a crime.. like rape, or mugging.. or murder somone from an opposing game..
......or they will still commit the crime but wear a disguise or a hood.
SOME crimes (crimes of passion?) are going to occur no matter what deterrents are in place.. Terrorism is one, but if you can catch them on vidieo you may be able to prevent the next one.. You can start your trail working backwards from identity back to their source..
Once again, cameras make investigations easier, but the success of historic investigations rarely hinged on surveilance camera evidence so we know it could be done without cameras.
The question is what amount of our privacy are we willing to give up for a little added safety by allowing investigations go a little easier.
Are you suggesting crime DOESN'T decrease where cameras have been installed? Because overall, that would be wrong!
Cameras have been in 7/11s, liquor stores and gas stations for decades.....they are still robbed.