There is a charity shop, which sells nothing but gives books away for free. They do accept optional donations of money, and any books donations so they have more books to give away for free.

Upon entering the charity shop, there is a sign saying that only a maximum of three books may be taken per visit.

Assume someone visiting the shop knowingly takes more than three books, without being caught at the time, but is discovered a short period of time later on CCTV.

In England and Wales, would this be a Criminal Offence or a Civil Matter?