Born to be discarded
Everyone has heard of them, but no one seeks to get in touch. The usual suspects are probably the props with the worst reputation. People who repeatedly submit themselves to the wildest suspicions just to maintain the suspense of the movie. Selfless creatures who willingly sacrifice their reputation on the altar of good cinema. Even so they don’t exist, they still deserve respect and dignity.
You have the suspect but you need a bunch of additional mug shots to be shown to the witness, or you have the match on a dating app, but there should be a couple of faces to be swiped away. Whatever kind of people you like to sort out, we’ll serve you all the non-existent persons you need.