Nick Shaw has written me a letter. Through the post. So this may be why he is a little late in joining the debate over pros and cons of cheap/pricey CCTV. (Actually, he has rather a good excuse for his belated contribution, but I am waiting for details before revealing it.)

He writes that you need cameras every which way: outside the store, at the entrance, at the rear, near the alcohol section and trained on your staff.

“I have been at my shop (The Sweet Shop, Halstead, Essex) for 30 years and I would like to pass on my experience. I have caught four staff over the years stealing from the till. It is only CCTV which gives you the absolute proof for instant dismissal.”

You need quality pictures, he points out. “It’s no good buying what looks like a good package if the picture doesn’t give you the detail you need.”

His new system, which has five cameras, hasn’t recorded over itself yet in two months. He recommends the company Y3K (0845 365 3000) and is now researching ways of remote viewing.

“Lastly,” he writes, “you need a second system of covert cameras such as (disguised as) a smoke alarm over the till. It also acts as a backup against a break-in where thieves have wised up to stealing the camera’s hard drive.”

Before anyone asks, I checked with the Information Commissioner to see whether staff had to be warned about covert cameras, but the fellow reckoned that the general sign you have up informing people that cameras were at work would suffice. You don’t have to tell them where the cameras are.