While Tara Lewis, played by Aisha Tyler, is talking with Spencer Reid in the break room, she makes a reference to her obsession with fossils to connect with the Truck Stop Strangler. This is a nod to her character on Friends (1994) who was a paleontologist.
Aisha Tyler (Dr. Tara Lewis) and Marisol Nichols (Agent Natalie Colfax) both appeared on 24 (2001) as CTU agents but never actually shared any screen time. Tyler appeared in Day 4, while Nichols appeared in Day 6.