| analyst(agent, hound, informer, reporter) |
| bird dog(expression, agent, informer, reporter) |
| bull(agent, informer, reporter, gumshoe) |
| constable(noun, agent, informer, reporter) |
| double agent(noun, expression, plant, agent) |
| emissary(noun, plant, watch, agent) |
| fink(agent, informer, reporter, gumshoe) |
| flatfoot(noun, agent, informer, reporter) |
| lookout(noun, plant, watch, guard, agent) |
| mole(noun, plant, watch, agent) |
| nark(agent, informer, reporter, gumshoe) |
| observer(noun, plant, agent, operative) |
| patrol(noun, plant, watch, guard, agent) |
| peeper(noun, agent, informer, reporter) |
| picket(noun, plant, watch, guard, agent) |
| plainclothes officer(expression, agent, hound, informer) |
| police officer(noun, expression, agent, informer) |
| prosecutor(agent, hound, informer, reporter) |
| reporter(agent, informer, gumshoe, investigator) |
| roper(agent, informer, reporter, gumshoe) |