At the end of the film, when Ed ( John Cusack ) shoots Rhodes ( Ray Liotta ), you can see Rhodes silently mouth "I didn't do this", and Ed mouth the reply "I know". Neither line is audible — the director opted to mute them, believing that hearing the exchange would make it obvious Rhodes wasn't the killer and thus lessen the impact of the true climax.
The probability that all ten characters share the same birthday is roughly 1 in 115,694,315,636,972,669,502,854 (around 1 in 115 sextillion).
A life-sized mannequin was made to represent the murdered character portrayed by Jake Busey, with a baseball bat lodged in his throat. One of the studio executives asked to keep the mannequin as a memento and stored it in his office cupboard. One night a cleaner opened the cupboard and was terrified; the mannequin was removed from the premises immediately afterwards.
"When I was going up the stairs / I met a man who wasn't there. / He wasn't there again today / I wish, I wish he'd go away." One character purports to have written these lines. In truth, the piece is the poem 'Antigonish' by William Hughes Mearns. The poem was subsequently adapted into a popular song, which brought it widespread recognition.
A number of alternate endings were filmed so as to keep the true conclusion under wraps.
The naked businessman Paris, bound to the bed at the start of the film Identity (2003), is one of Malcolm's identities; he is also the agent whom Caroline Suzanne speaks to on the phone. He was originally intended to be the first of Malcolm's identities to 'die', but those scenes were cut from the film.
The complete list of the motel's characters by full name is as follows: Edward 'Ed' Dakota, Samuel Rhodes, Paris Nevada, George York, Alice York, Timmy York, Larry Washington, Caroline Suzanne, Virginia "Ginny" Isiana, Lou Isiana and Robert Maine.
Whilst Caroline Suzanne's standing at the mirror, the killer can be glimpsed in the reflection at her motel room window through a muslin drape.
Some location filming took place in Lancaster and elsewhere in Los Angeles County. However, the majority of the film was shot on a huge soundstage at Sony Studios in Culver City — the same studio that once housed the set for the Emerald City in The Wizard of Oz (1939).
Although "Identity" is not a direct remake of the novel/film "And Then There Were None" (sometimes known as "Ten Little Indians") written by Agatha Christie, the film borrows several plot elements from that story. The dialogue even alludes to "that film in which ten strangers travelled to an island and then died one by one." Whereas stage and screen adaptations often opt for a happier resolution, "Identity" sticks to the novel's original ending: the murderer is revealed to be one of the victims who faked their death, and nobody survives the incident. In the book, the killer takes their own life after persuading the final survivor to do the same.
The corpse of the motel manager, concealed in the freezer by Larry, was portrayed by Stuart M. Besser, who served as the film's executive producer and production manager.
In the original draft the killer was written as an Australian expatriate schoolteacher. It was later concluded that depicting a woman teacher as a serial killer would likely be poorly received by parents' organisations, so the idea was dropped.
John Cusack and Amanda Peet later went on to star as the leads in 2012 (2009), in which they portray a recently divorced couple. Cusack also appears as a driver in both films.
This marked Frederick Coffin's final on-screen performance; he died on 31 July 2003, aged 60.
Bret Loehr has only a single line of dialogue in the entire film. Moreover, part of that line is delivered first by Pruitt Taylor Vince.
The volume visible in Ed's car as he gives Paris a lift is 'Being and Nothingness' by Jean-Paul Sartre.
Death toll stands at 14. That figure does not include the girl Ed failed to save, nor the six people Malcolm murdered previously.
Leila Kenzle was occasionally substituted by a dummy during filming, for instance immediately after her character's death.
While being led to the toilet, the inmate starts to sing 'I Got Stripes', a prison song by Johnny Cash, who died the year following the film's release.
James Mangold: [Cash] The character portrayed by Jake Busey is humming lines from a well-known song by Johnny Cash: "I got stripes, stripes on my shoulders." Mangold's next film was the Cash biopic Walk the Line (2005).
Marshall Bell and Jake Busey both had roles in the film Starship Troopers (1997).
When Rhodes slips on his jacket and leaves his room, a small hole and a bloodstain are plainly visible on the back of his shirt. Later, after detaining Maine, he brutally beats him — conduct untypical of a police officer, particularly with another person present.
Marshall Bell and John Cusack had earlier appeared together in Stand by Me (1986), playing father and son.
The prison ID numbers for Samuel Rhoades' and Robert Maine' consist of the exact same digits, each appearing with identical frequency — two 1s, one 2, two 7s, two 3s, one 8 and one 9 — yet the sequence differs: Rhoades's ID is 728-337191, whilst Maine's is 139-782713.
This marks the second occasion on which composer Alan Silvestri stepped in to replace a score by Angelo Badalamenti. The first instance was the film Shattered (1991).
