Crossword Clue:

to investigate thoroughly

AnswerCrossword Clue
VETThoroughly investigate
PROBEInvestigate thoroughly
RESEARCHInvestigate thoroughly
VETInvestigate thoroughly
SUSS-- out (investigate, to a Brit)
CHECKUPONInvestigate from time to time
MUSIC"..., to create harmony, must investigate discord" (Plutarch)