Joe Carroll, the name of the serial killer, was also an alias used by London "Sketchbook killer" John Sweeney.
In a recent interview, Kevin Williamson revealed that one of the first ideas for this show was in his draft for Scream 3 (2000), the one movie of the franchise that he ended up not writing. The idea was that Sidney Prescott would arrive to a house to find a group of murdered people, implying that she was too late to save them. The twist would have been that at one moment, they would all start getting up, alive, and it would be revealed that they were all part of a cult following, "Ghostface."
The characters Mark and Luke, the twins in season two, are played by one actor, Sam Underwood. Every scene that they are in together had to be filmed twice and pieced together post-production. A few scenes, however, are filmed with stunt double Shan Agish switching out roles.
Both Kevin Bacon and Shawn Ashmore have roles in X-Men movies; Ashmore played Iceman in X-Men (2000), X2: X-Men United (2003), X-Men: The Last Stand (2006) and X-Men: Days of Future Past (2014), with Bacon appearing solely as the villain in X-Men: First Class (2009), which Ashmore does not appear in.
The Following (2013-2015) shared a lot of actors with the show Unforgettable (2011), including: Annie Parisse, Kyle Catlett, Marin Ireland and Tom Lipinski.
Jeananne Goossen was originally cast as a series regular in the role of Agent Jennifer Mason but after the pilot episode, her character was written off and replaced with Agent Debra Parker, and Annie Parisse was cast.
Jessica Stroup, Kevin Bacon, Connie Nielsen and Shawn Ashmore have all starred in superhero movies and TV shows: Jessica Stroup on the Marvel-Netflix series Iron Fist (2017), Kevin Bacon in X-Men: First Class (2009), Connie Nielsen in Wonder Woman (2017), and Shawn Ashmore in X-Men (2000), X2: X-Men United (2003), X-Men: The Last Stand (2006) and X-Men: Days of Future Past (2014).