Detective

12 clues
PI
Dick
Shamus
Investigator
Whodunit hero
Queen, for one
Poirot, for one
Peter Gunn e.g.
Spade or Marlowe
Spade or Spenser
Private investigator
Protector of the public
Similar answers:
Active
Activecase
Activecomponent
Activeduty
Activeinterests
Actively
Activeplay
Activerole
Activeroster
Actives
Activeservice
Activevoice
Activevolcano
Activevolcanoes
Activewear
Activeyeast
Adddetergents
Addictive
Adjective
Aptitudetest