Almost all locations used for filming were the genuine locations where the events occurred. The tea shop where Honorah Parker ate her last meal was knocked down a few days after the shoot ended. According to director Peter Jackson, when they got to the location of the murder on the dirt path, it was eerily quiet; the birds stopped singing, and it didn't seem right. So they moved along a couple of hundred yards.
Since the Parker-Hulme murder had been an infamous crime that was strongly sensationalized in New Zealand history Jackson decided rather than do a film that would be a historical look back at the crime to instead create a drama about Parker and Hulme's intense friendship. In addition to reading Pauline Parker's diary Jackson and company undertook a nation wide search for anyone who had known the girls and interviewed them to get a closer look at their lives.
Juliet Hulme was revealed to be mystery writer Anne Perry who came forward and revealed her real identity in 1994 during the making of the film, but all attempts to find Pauline Parker failed. In 1997, Pauline Parker was finally traced to a rundown cottage on a farm near Strood, Kent, England, where she currently runs a children's riding school. Since assuming the name of Hilary Nathan, she has become a devout Catholic and devoted her life to handicapped children.
Before the murder, Juliet is seen pacing nervously around Pauline's bedroom, saying "Your mother is rather a miserable woman...I think she knows what's going to happen. She doesn't appear to bear us any grudge." This line was paraphrased from a statement by the real Juliet to her psychologist prior to the trial, when the two girls were being evaluated for an insanity plea.
Until 1973, homosexuality was considered a mental disorder associated with deviant behavior including, but not limited to, murder. Because of the closeness of Hulme and Parker's friendship, there was a lot of speculation about whether or not they were lesbians. When Hulme was asked during the trial if she and Pauline had had sex, she replied, "How could we? We are both women." To this day, Anne Perry (the name Juliet assumed after prison) continues to insist that there was never a sexual element to the friendship.
When Juliet Hulme is introduced in the movie, it depicts her being called down by both her French and Art teachers. However, none of Hulme's instructors ever spoke to her harshly or even punished her. In fact, the opposite was true. According to classmates of Hulme, because her father was Rector of Canterbury University College and her family was English, she was treated very well by students and instructors alike. Girls Hulme attended classes with have stated in interviews that when a group of them got caught in mischief, they would simply have Hulme say it was her idea and there would be no consequences. Hulme's instructors gave her special allowances based on her father's position, even though he was not well liked by his colleagues, and Hulme's classmates found her very exotic because she was from England.
Nowhere in the film is it stated that Juliet was, in fact, the famous mystery writer Anne Perry, or even that she changed her name after the events. While Perry insisted that her true identity was an "open secret" amongst New Zealand literary circles, her connection was not confirmed until after the film was released--in part because the film revived interest in learning what had become of the two girls.
The closing text states that it was a condition of the girls' release that they never meet again. This is not true. While the court ordered that they be housed in separate prisons and forbidden to communicate, Juliet's release in November 1959 was unconditional, and the only condition on Pauline's release a few weeks later was that she remain on parole in New Zealand for the next two years. However, it appears that the girls never sought each other out after their release, even though they were legally free to do so. Juliet (now called Anne Perry) has stated in interviews that the last time they saw one another was at their sentencing in 1954 and that she herself has no interest in ever reuniting with Pauline.
When Pauline visits Juliet at the hospital, she admires the red knitting on which Juliet is working. Juliet tells her "it's for you." Several scenes later, when Juliet and Pauline are seated on the bus during the "The Ones That I Worship" poem, Pauline is wearing the now-complete red sweater.
Based largely on information gathered and further detailed in the 2011 book "Anne Perry and The Murder of The Century" (Peter Graham). Excellent source for more real-life information as covered in this film.
The film was later parodied in the 20th season of the long running animated comedy "The Simpsons". In Lisa the Drama Queen (#20.9) Lisa Simpson becomes friends with an intelligent girl named Juliet Hobbes and they both create a fantasy world and Marge decides that Lisa is not to see Juliet anymore, when Marge believes that their friendship has gone too far. Emily Blunt whom provided the voice of Juliet Hobbes, later provided the voice of Juliet in the animated 2011 film "Gnomeo and Juliet".
The shrine that the girls build in the woods includes the following: Mario Lanza (operatic film tenor), James Mason(actor), Mel Ferrer (actor), Jussi Björling(operatic tenor) and Orson Welles (actor).These also figure in the fantasy sequences.
Information and details presented in this film are hugely expanded upon with much further research and detailed facts in the 2011 book "So Brilliantly Clever: Parker, Hulme and the Murder That Shocked a Nation" (published in the States as "Anne Perry and the Murder of the Century").
One of the widest points of speculation is whether or not the real Pauline and Juliet had a sexual relationship, with Pauline's diary implying strongly that they did and Juliet/Anne Perry insisting they did not. Peter Jackson instructed his actresses to perform their love scenes as if they were two devoted friends role-playing as their favorite fictional characters.
The trivia item below may give away important plot points.
Unbelievable though it may seem, the real-life murder was much more violent than the one in the movie. PJ doesn't show us much and does an amazing job with sound, but eventually only the first eight blows are depicted in the film. The real Honorah Parker suffered around 45 different wounds on her face and skull, and had been found face upward as opposed to what was shown in the movie. Furthermore, she had been held down by the throat during most of the attack.