Visible crew/equipment: In the opening scene, the camera and camera man can be seen reflected in the knife. (00:01:20)
Factual error: In the opening club scene, the main song played is "True Faith" by New Order. The early part of the movie takes place in 1986, and the song was released in late July 1987. (00:03:45)
Factual error: The phone by Patrick's bed is the BeoCom 1401 from Bang and Olufsen, a model introduced in 1991, well after the movie events. (00:05:00)
Factual error: When we get a glimpse of Patrick Bateman's closet as he narrates his morning routine wearing the mint mask, you can see next to a red capped bottle of Yves Laurent a very distinct bottle with no brand label but a unique design, with its small bumps and decorated cap. It's a bottle of Eaux de Caron Pure, a perfume introduced in 1996, a decade after the events of the movie. (00:06:30)
Visible crew/equipment: After the beginning of the movie where there is an aerial shot of New York City just before we see Patrick getting at his office, the filming helicopter can be briefly seen reflected on one of the buildings' glass on the left side of the screen while it films the scene. (00:07:13)
Visible crew/equipment: The first time Patrick Bateman enters his office (listening to "Walking on sunshine") you can see a boom microphone reflected in the glass partition of his secretary's office area. (00:07:44)
Continuity mistake: Patrick casually puts his Walkman on the desk as he enters his office for the first time in the movie. The Walkman and headphones are in a different position in the next shot before he had a chance to touch anything. (00:07:45)
Continuity mistake: Immediately after Patrick asks his secretary for mineral water, he is holding a filled glass at the bottom of the frame. The glass appears before she has even had a chance to move, let alone fetch it for him. (00:08:25)
Factual error: We see for the first time Patrick with his "supposed fiancée" during a cab drive. Towards the beginning of the ride, the cab drives between a firetruck and an ambulance, both with the insignia of the F.D.N.Y. The ambulance service wasn't introduced in the FD until the merger with NYC*EMS, which happened in the mid-90s, almost a decade after the events of the movie. (00:09:15)
Factual error: On the way to the dinner at Espace with his girlfriend, Bateman is listening, or trying to, to "the new Robert Palmer tape." Which is kinda uncanny, considering that the movie only time references set it in 1987 (that particular part in late 1986), and the song, "Simply Irresistible," was released in May 1988. (00:09:25)
Visible crew/equipment: In the scene where Patrick Bateman is walking the streets, just before that encounter with the lady who is waiting for the red light to change, you can see the camera crew reflected on the store windows. (00:12:30)
Visible crew/equipment: When Patrick is at the dry cleaners, and arguing with the owners, a woman called Victoria comes in and offers to get Patrick's clothes cleaned for him. Just before Patrick leaves he says "Oh boy, I've got to go. Thank you, Victoria" and you can see the boom microphone reflected in the glass door (just above Victoria's head). (00:14:17)
Factual error: The actual footage playing during the phone call with Courtney is from the 1998 porn "White Angel" (around the 40-minute mark, in case you want to research the material), making it anachronistic for a movie set over 10 years earlier. (00:14:35)
Continuity mistake: When Patrick calls Courtney to invite her to Dorsia, the porn he is watching on tape is supposed to be "Inside Lydia's a55" (well, I can't post the naughty word here; you get the idea). The case turns around in Patrick's hand between shots. (00:14:55)
Continuity mistake: We see Patrick dial the number of the elusive Dorsia restaurant for the first time; a noticeable long lock of hair dangles in front of his forehead. In close-up (when he is laughed off over the phone), his forehead is clear, no wisps in view. (00:15:25)
Continuity mistake: In the office scene where Paul Allen walks up to Patrick Bateman and mistakes him for Marcus, Paul crosses his arms as he starts talking to Bateman. The angle changes and his arms are suddenly straight. (00:17:30)

Other mistake: Several close-ups of the business cards of Patrick Bateman and his associates reveal a misspelling of the word "Acquisitions" (the "c" is missing - not a small error, given that this is the name of their department). (00:18:35)
Other mistake: Despite the intended uniformity of misspells of the department name, Bateman's card actually has an added mistake, lacking the space between the ampersand and the second name (it's "Pierce & Pierce" instead of "Pierce and Pierce"). It should also be noted that not only do they share the remaining misspelling, but their contact info is also exactly the same, including the phone number. (00:18:45)

Continuity mistake: When Bryce pulls out Paul Allen's card to show it to Patrick, he holds it in different ways between shots. (00:19:44)
Continuity mistake: At the Xmas party, someone puts plush antlers on Patrick's head while Evelyn shows him her new pet Vietnamese pot-bellied pig. The antlers are in front of Christian Bale's ears. He excuses himself to go talk to Paul, and the antlers are now behind his ears. (00:24:00)






Answer: The situation is intentionally left vague. The homeless man being murdered wouldn't necessarily make the news in the time (there were over 4000 murders in 1989-90 when the book and movie are set). He and his friends are so alike that they continually mistake each other for others. The prostitutes would likely be loathe to call the police because they might be arrested themselves and he would likely get off with a much better lawyer.
Greg Dwyer
Very true. It is also true that both the director and the writer of the novel are adamant that they don't like at all the idea that people assume he didn't kill anyone and it's all in his mind, even if not everything may happen literally as shown (like the ATM cat-killing message).
Sammo ★