On Brody's laptop is a label that reads "You can't blame a writer for what the characters say." This is a quote from Truman Capote, who was also a true crime novelist, like Brody. Shelby insultingly calls Brody "Capote" late in the film.
The crime suspect board on Brody's wall features several members of the crew including Cinematographer Matt S. Bell, Production Designer Dallas Montgomery, and AD Kevin Lorio.
Shelby reads a negative review of Brody's "Deadly Affair" book. "A Deadly Affair" is the title of a previous film directed by David Bush, also starring Austin Highsmith Garces. The quote Shelby reads is an actual quote from a real review of that film.
Megan Park is married to Tyler Hilton. Tyler Hilton and Stephen Colletti worked together on the show "One Tree Hill" (2003)
When Shelby and Natalie consider suspects at the bar, Natalie comments that what they're doing is a bit like the board-game, Clue. The rest of the patrons of the bar are dressed like the characters in that game.