Check, examine (3)
I believe the answer is:
vet
This clue is a double definition.
'check' is the first definition.
(to vet someone is to check their background)
'examine' is the second definition.
(I know this)
(Other definitions for vet that I've seen before include "'Examine this doctor, in short (3)'" , "Dog doc?" , "Critically examine" , "solider once" , "Check someone for suitability" .)