| nark(agent, spy, police, informer, reporter) |
| peeper(agent, spy, police, informer, reporter) |
| plainclothes officer(expression, agent, spy, hound, police) |
| police officer(expression, agent, spy, informer, reporter) |
| private detective(noun, private) |
| private dick |
| private eye(expression, agent, spy, informer, gumshoe) |
| private investigator(expression, agent, spy, informer, gumshoe) |
| prosecutor(agent, spy, hound, police, informer) |
| reporter(agent, spy, informer, gumshoe, investigator) |
| roper(agent, spy, police, informer, reporter) |
| scout(agent, spy, informer, reporter, gumshoe) |
| sergeant(agent, spy, police, informer, reporter) |
| shadow(agent, spy, informer, reporter, gumshoe) |
| shamus(agent, spy, police, informer, reporter) |
| shoofly(agent, spy, police, informer, reporter) |
| skip tracer |
| sleuth(agent, spy, hound, informer, reporter) |
| sleuthhound |
| slewfoot(agent, spy, police, informer, reporter) |