inquirer, researcher, detective, tester, inspector, reviewer, analyst, auditor, reviewing board member, prosecutor; see also examiner. see also detective, policeman, spy.

Investigators include: sleuth, detective, spy, counterspy, plainclothesman, police inspector, district attorney, prosecuting attorney, government agent, Federal agent, fed*, census taker, insurance investigator, Treasury agent, T-man, FBI agent, CIA agent, Gestapo agent, double agent, narcotics agent, narc*, ombudsman, plain-clothes man, secret police, secret agent, informer, G-man*, snooper*, dick*, operative*, undercover man*, flatfoot*, private eye*, spotter*;