Originally Posted by
RandomNobody
Is the CBP limited to the NCIC database? In my line of work, I know plenty of people that can pass a 4473 with a clean NICS check, but can't pass a security clearance.
Also, lots of pilots are tripped up by the 8500-8 questionnaire when they go for a medical exam and answer "no" to to the "have you ever been arrested for DUI" question with an expunged DUI arrest. The FAA Aeromedical branch still finds it even though it doesn't come up in a NICS check.