It could have been someone from a previous study.

Is he? Are you kidding? What else did you see? Well, if we're lucky, we can make it to… Organic, huh? Loli Looking for Tracy. It's the parking brake! They took my radio and my bass. She's got the phones. Hand that over too, big fella. It's disgusting. This and that. No matter what you think they did, just… Uh, it's a GPS.