Bow Street runner
DT
FBI
FBI agent
Federal
G-man
MP
Pinkerton
Secret Service
Sherlock
Sherlock Holmes
T-man
asker
bailiff
beadle
beagle
bound bailiff
captain
catchpole
catechist
chief of police
commissioner
constable
consulting detective
cop
copper
cross-interrogator
cross-questioner
deputy
deputy sheriff
dick
examiner
eye
fed
federal
flic
gendarme
government man
gumshoe
hawkshaw
hotel detective
house detective
house dick
inquirer
inquiry agent
inquisitionist
inquisitor
inspector
interlocutor
actor
clerk
engineer
guy
investigator
lawyer
nurse
officer
physician
pilot
police
politician
reporter
scientist
sergeant
spy
surgeon
affective
anti-infective
collective
connective
convective
corrective
defective
directive
effective
elective
ineffective
infective
introspective
invective
irrespective
objective
perspective
projective
prospective
protective
reflective
respective
retrospective
selective
subjective