Bow Street runner
FBI
FBI agent
Federal
G-man
MP
Secret Service
Sherlock Holmes
T-man
agent
amanuensis
baggage agent
bailiff
beadle
beagle
bound bailiff
business agent
captain
catchpole
chief of police
claim agent
clerk
commercial agent
commission agent
commissioner
consignee
constable
customer agent
deputy
deputy sheriff
detective
dupe
factor
federal
federal agent
flic
freight agent
functionary
gendarme
general agent
government man
hotel detective
house detective
house dick
implement
inquiry agent
inspector
instrument
insurance agent
investigator
feed
central bank
Ed
Fred
Freda
Ged
Head
Jed
Med
Ned
Read
Red
Said
Ted
Thoroughbred
Wed
abed
ahead
bed
behead
bled
bread
bred
dead
dread
dred
ed
embed
fled
fred
ged
head
imbed
infrared
instead
interbred
lead
led
med
misled
misread
ned
overfed
overhead
pled
purebred
read
red
redd
retread
said
shed