In the book on which the film is based, the characters played by Stana Katic and Darby Stanchfield are sisters. On the television series Castle (2009), Katic played Kate Beckett, the wife of Richard Castle, the show's lead character, and Stanchfield played his first ex-wife.
In this film, Jake says to Rachel, "I'm guessing lonely nights... watching Sherlock Holmes on TV with ice cream and flannel PJs.". Raza Jaffrey, who plays Jake, had a recurring role in Elementary (2012), which is a TV show based on Sherlock Holmes.
The film's basic, underlying plot point is Rachel's desire to learn how her brother died. In Truth About Kerry (2010), Stana Katic plays a woman of similar single-minded determination trying to find out how her best friend died.