Did you end up calling the police, or did you end up letting them go with a slap on the wrist??
I remember working in retail, and the amount of times the manager would let people go with a slap on the wrist was shocking. When I became assistant manager and no higher manger was on duty, I would be mean and call the police. Even if the company decided to not press charges, it would scare the daylights out of people.
When I left the company, we had hired an ex-shoplifter in security who had stolen tens of thousands of pounds worth of stuff from anywhere and everywhere. Apparently she ended up getting caught because she tried to steal a book from a chariety shop. Her reasoning, the rush?
Its a shame people have to resort to steal and its horrible people do it from charity shops.