i suggest a twin camera module, one in the shop that connect to the mobile phone of the owner. then the normal shop security system linked to the mobile phone program, all that’s left is to write the program for what its to do when it sees what.
Definitely, a camera module will be needed. The law will want to get the face of the thief or something after a message has been triggered on the users phone but it takes a while to get there (After the whole had already happened). Nice