Trivia: When Ted and Robin are at the restaurant, they are accidentally sent a champagne glass with an engagement ring in. A man then claims the ring and proposes to his girlfriend. This couple really did get engaged on the show - the guy set up the surprise proposal, as his girlfriend thought they were just there as extras.
Trivia: At around 5 mins 11 seconds into the episode, Vincent Nigel-Murrey and Dr. Saroyan are discussing the bones on the forensic platform. In the background of a shot of Vincent, the x-ray on the screen is of Homer Simpson's head in the middle of the screen, instead of a real human skull.
Trivia: Although they didn't have any scenes together, Kevin McKidd (Vorenus) and Tobias Menzies (Brutus) would discuss their characters and brainstorm about how to portray them, because they felt their characters went through very similar moral conflicts. Confirmed by Kevin McKidd on the season one DVD commentary.
Trivia: Christina is thrown out of her house after the revelation that she's been lying about her life, and leaves town on a Greyhound as the camera pans down to reveal a sign saying "Now leaving Point Pleasant. Please come back soon.". This is almost identical (both the shot of the sign and the story behind it) to the Buffy The Vampire Slayer episode "Becoming" (2x21) - both the show's executive producer (Marti Noxon) and the writer of this episode (Diego Gutierrez) are former BtVS writers.
Trivia: The episode revolves around a man killing people with the same first names as the thirteen apostles (Mary Magdalene being the 13th), and killing them in a similar fashion in which the apostles died. At one point, Colby and David find a box with a mannequin's head in it. This is a reference to the film Se7en, in which seven people are killed for committing one of the seven deadly sins. The film ends with the main characters finding an actual head in a box.