If you want the secrets of those cameras...
I worked a *large* camera operations center for a major retail store in a very, very big city. The total cameras were about 80, with a single control center. Usually there's only one person on the pad at a time.
Secret number one is that much of the time we're watching employees, not shoppers. Employees count for the majority of a store's shrink.
Secret two is that you're more likely to get away with it than not. It's impossible to watch hundreds of people at once. Cameras will watch frequently stolen items, or monitor for people that look suspicous. Bags that aren't from that store. Booster boxes. People looking around, acting suspicous. There's actually ways to detect if you're being tracked by cameras but I won't divulge those...
Secret three is that in order to be successfully prosecuted you need to (typically) be caught concealing, then leaving the premise with no breaks in between. A good LP person may lose track of you and stop you outside the store anyhow, but the rule is: if you lost track of a person between concealment and exit and you're unsure if they ditched the item, you cannot stop them. The liability is huge.
Secret four: You set off the sensormatic. Doesn't matter, you can't be detained on that single event, it must be in conjunction with a witnessed concealment.
Secret five: Sensormatic. Aluminum foil inside a closed bag, surrounding the item will keep it from going off.
I shouldn't of said all those things, but there you go.