* The detective found a crucial clue in the form of a fingerprint on the windowsill.
* The cryptic message left behind by the kidnapper contained a few clues about the victim's location.
* The missing piece of the puzzle gave us a vital clue to solving the mystery.
* Even the smallest detail could be a clue when investigating a crime.
* She tried to decipher the clues in the riddle, but she couldn't figure it out.