The sign for "suspect" is done by getting a suspicious look on your face and then scratching the side of your forehead a bit with with your index finger.
SUSPECT / SUSPICIOUS:
Also see: PARANOID
Notes:A student asked me if this sign (above) would be good to use for the concept of a criminal suspect.
You could use this sign as part of an initial description, something along the lines of: POLICE SUSPECT INDEX-"him" MAN THIEF. After that you would simply point in the direction of the identified suspect (either absent or present). However, it would be just as effective to use the sign "THINK" in that sentence. Or use "THINK MAYBE."
Notes: