This query came via our website ( from 'Natalie', who wanted to know whether previous as well as current CCTV footage can be used in court to help convict a shoplifter, and whether the jury gets to view the footage.
I did leave messages with the Association of Chief Police Officers' press office, but am still waiting for a response many days later.
However, I was enlightened a little by Chris Bird of CCTV Linc, which supplies digital systems to shops, councils and colleges.
His world-weary answer was: "Every county changes the law to suit itself. The police do as much as they can to proceed and the defence will do what they can to get out of it."
So the answer is: "It depends".