Surely the deterrent is the possibility of being caught?

If you're more likely to be caught due to the surveillance, logic would dictate that it's the greater deterrent.

My brother had his window smashed and bag stolen under a cctv camera in London. The police never even investigated.

I would hazard to say that wouldn't have happened had a police officer been stood there instead.

Some major shops in the UK have photographs of police officers on the door, because it reduces theft!

Because it’s hard to investigate that with old cctv tech. Unless the person on the video was easily identifiable, it’s hard to do anything to follow up. With the new networked AI tech you could search for the person across the whole network to find out where they went / get a better view of them.

I think this says more about dwindling police budgets than about the efficacy of surveillance or bobbies on the beat.