N3 - 検査けんさ
inspection (e.g. customs, factory), examination
N3 - 調査ちょうさ
investigation, examination, inquiry, survey
N2 - 巡査じゅんさ
police, policeman
N1 - 審査しんさ
judging, inspection, examination, investigation
N1 - 捜査そうさ
search (esp. in criminal investigations), investigation