The film's most striking element is its presentation. Though there are few periods of "traditional" movie storytelling, most of the movie is presented as Chapman's diary. Nearly all of the dialogue is narration from Chapman and combined with variety of quickly edited footage. It's both disorienting and hard to follow, but when taken with the narration, it reinforces the fact that Chapman's mind isn't quite right.
The story opens three months before the murder. Chapman (Jonas Bell) is a self-described outcast and nobody of any importance. He hates his mother, fantasizes about killing his father and makes prank calls to a pay phone outside his apartment telling whoever answers, "Bang, Bang. You're dead". Chapman eventually finds purpose in his life when he reads "The Catcher in the Rye", at which point he begins to identify with Holden Caulfield. He also finds his own "fat guy in the hotel" in the guise of John Lennon. Although a fan of his music, Chapman begins to see Lennon as a phony; a person whose lyrics say to, "Imagine no possessions...", yet he is a multimillionaire.
Although a more recent movie, the film feels like it was made in the early 80's. The film quality has a grainy, deteriorated look reminiscent of Taxi Driver, which in an odd way is sort of fitting considering that Travis and Chapman share somewhat similar mindsets (at one point Chapman even quotes Travis). Clips from the news and radio shows are intertwined throughout the film to give a sense of how big an impact Chapman's actions had. I was a year old when Lennon was killed and my only analogy is the frenzy following the death of Princess Di. However, after speaking to my mom and uncle, it seems like the film gives a good account.
More than anything else, I loved how the film doesn't try to make excuses from Chapman. There were times where I understood Chapman's reasoning, but there isn't an overt attempt to make him sympathetic. On that same token, it only focuses on the "Catcher in the Rye" angle and makes little mention of Chapman's psychological problems. The editing makes it clear that things aren't right in his head, but things like the "little people" that he would talk to, are left mostly in the deleted scenes. Given how balanced the movie's portrayal is, I'm guessing they were left out due to time constraints, though it doesn't give as full an account as it could. At the same time, when taken alongside "The Catcher in the Rye", it makes Chapman just as unreliable a narrator as Holden. The absence of some scenes does, however, screw with parts of the ending since there are small references to cut scenes.
Overall, I really enjoyed The Killing of John Lennon, but then I tend to like off-beat, psychological films. The odd pacing might throw off some viewers, but it does a good enough job at keeping a consistent story that you shouldn't become lost. Major John Lennon fans might want to sit this one out. Again, it doesn't make excuses for Chapman, though watching some of the footage and the actual murder might be a little too much.