Hello. (Not sure where to go for input.) Can someone confirm the identity of a background cast member? S6E6 Shawn Interrupted - In the opening, victim Sheila Hanson is shown in a news thumbnail on Lassiter's tv, but in the next scene at SBPD a woman wearing green walks behind the group. She looks eerily similar to the actress playing Sheila Hanson (Sally Bishop). I've tried to confirm via trivia, wikis, and interviews. I think they used Sally Bishop as a background extra in a passing appearance to tease Psych-os.
Using the same person to play multiple minor roles is not that uncommon, so you could certainly be right. Extras aren't credited, however, so it would be hard to find evidence of her involvement in the second scene.
I see what you mean. A good way to put it would be that recurring cast members play characters that can appear independently of subplotlines, whereas guest star characters are wholly dependent on (one or more of) those.
Using this definition, I propose that the following cast members currently in the Recurring Cast category be considered guest stars instead:
Ed Lauter (his second appearance as Ed Dykstra is simply in continuation of an earlier subplotline);