Diligent and thorough in inquiry or investigation(adjective)
WordNet. Princeton University. 2010.
Use "inquisitory" in a sentence
"A wonderful message indeed, considering that Mr. Sullivan himself was the chief architect of that inquisitory foray, which he pressed unrelentingly."
"From abroad this looks like a rebirth of inquisitory methods."
"Broad investigatory, inquisitory and subpoena powers were given to that body of citizens drawn from the community; like powers were not intended to be in the hands of the prosecutors of crime."