You have a really great concept here! I love the idea of using the security cameras to catch the thief!
I think it could be even better with a little more going on gameplay-wise. For example, maybe I could be checking out one customer's items while also keeping an eye on the cameras to see if someone else is stealing XD
But overall, it's a really fun idea! I also enjoyed the character interactions a lot. There's a surprising amount of dialogue, and the conversations are really fun!!