| roper(agent, informer, gumshoe, investigator) |
| scout(agent, informer, messenger, gumshoe) |
| sergeant(agent, informer, gumshoe, investigator) |
| shadow(agent, informer, gumshoe, investigator) |
| shamus(agent, informer, gumshoe, investigator) |
| shoofly(agent, informer, gumshoe, investigator) |
| sleuth(agent, informer, gumshoe, investigator) |
| slewfoot(agent, informer, gumshoe, investigator) |
| snoop(agent, informer, gumshoe, investigator) |
| bull(agent, informer, gumshoe, investigator) |
| cop(agent, informer, gumshoe, investigator) |
| dick(agent, informer, gumshoe, investigator) |
| eye(agent, informer, gumshoe, investigator) |
| fed(agent, informer, gumshoe, investigator) |
| fink(agent, sneak, informer, informant) |
| tail(agent, informer, gumshoe, investigator) |