You can get access to security cameras, but you'll have to go hunting a bit. Some cameras are operated by local government, but the vast majority are run by privately and you'd need to track down each operator and request the relevant material. Depending how long its been they may or may not still have it, and I imagine despite the legal requirement to provide access a lot of people will initially refuse to go trawling through their CCTV archives to find the relevant material.