Fuente: WIPO "tomato" A system and method to evaluate transactions executed at self-server point-of-sale (POS) terminals located at retail stores with improved ability to identify potential shoplifting incidents. The service determines most stolen K items (MSKI) from a transaction history and shopping theft data of the retail store, where K is an integer value greater than one. The service generates a set of not stolen K items (NSKI) based on market basket analysis of the transaction history. The service defines suspect transaction classes based on the MSKI and the NSKI and generates an alert for a current transaction at the retail store when items in the current transaction match one of the suspect transaction classes.