The answer to each clue below highlights one particular letter (different each time). Wordplay is fair play.

1. Letter our for a stroll
2. Photographer of a letter.
3.One who can't hold a letter
4. Naval officer in charge of a letter
5. Undercover operation to trap a letter.
6. Weeping letter
7. Letter in a track meet
8. Letter that breaks out of jail

Answers:

1. J walking
2. P shooter
3. I dropper
4. C captain
5. B sting
6. D crying 
7. E racing
8. S caper

Credit #1-5: Fred Jackson III