There is a reference made by Gus that Penny Chalmers (Kate Micucci) was in a bologna commercial. This is a nod to Kate Micucci being in Hillshire Farm Meat commercials.
Kate Micucci plays a character named Penny Chalmers. This is in fact the name of one of the behind the scenes crew members for the Psych series.
First episode directed by Jennifer Chambers Lynch, daughter of David Lynch, whose show, Twin Peaks, was the basis for the episode, Dual Spires.
Andy Berman, who plays Singh, was a writer on this (and many other) episodes. This is not his first bit part on Psych.
Whip Chatterly asks, "Am I the only one who thought Mary Lightly was the killer?" in reference to the book written by Mr. Yang in the Yin/Yang episodes. This calls back to Shawn twice mistakenly pinning Mary as the murderer, in both An Evening with Mr. Yang (2009) and Mr. Yin Presents (2010).