Although CBP had controls over its polygraph examination process, a key control over its review and approval process was not always operating as intended. Specifically, the polygraph quality control program may not have always conducted independent and objective reviews (blind reviews) of polygraph examination results, as required. We also determined that 96 percent of the complaints we reviewed were unfounded or ambiguous. Nevertheless, CBP did not have a formal complaint review process, which led to inconsistent and subjective reviews. This approach risks not finding or properly addressing issues contained in the complaints.