The system and method described herein may be used to make a binary determination of whether to initiate an in-trip audit of self-scans in a self-checkout system. For example, the system may receive one or more audit parameters that are used to calculate an audit score. The audit score may be compared to a predefined audit threshold to determine, during a shopping trip, whether to initiate the in-trip audit. After or in combination with making the binary determination, the system may make a probabilistic determination of whether to initiate an audit based on historical audit points associated with the shopper. The audit points are incremented or decremented based on prior audits and other characteristics of the shopper.