A method for determining a confidence level to be used in identifying a vehicle. The method includes receiving a vehicle image, extracting a license plate image from the at least one vehicle image, determining a license plate number and associated confidence level based upon the license plate image, and comparing the associated confidence level against a confidence threshold. If the associated confidence level is below the confidence threshold, the method further includes extracting auxiliary data from the at least one vehicle image, corresponding the extracted auxiliary data and a set of stored auxiliary data, and updating the associated confidence level to produce an updated confidence level based upon the correspondence of the extracted auxiliary data and the set of stored auxiliary data.