While at a bar with Detective Drowatzky, Bill Tench references Uri Geller when the subject of psychics comes up. Uri Geller was an illusionist and claimed to be psychic. He is best known for his trademark performances of spoon bending.
While discussing killers with a specific name, Zodiac is also mentioned. David Fincher has directed Zodiac (2007), based on him.
At the beginning of this episode, BTK is watching Barbara Eden's 1978 film "Harper Valley P.T.A. (1978)" on television.