Turk is wearing a "Spread The Word To End The Word" t-shirt, which is a movement to stop people from using the R-word to describe people with Down syndrome. John C. McGinley's (Cox) son, Max, has Down syndrome and McGinley is a vocal supporter of the cause.
When Denise is looking for Drew, she describes him as having a "serial killer vibe". The actor Michael Mosley played a serial killer named Everett Lynch in the last season of Criminal Minds (2005).
Final episode of Ken Jenkins as Dr. Kelso