Continuity mistake: When Graham and Hannibal are talking for the first time, Hannibal walks right up to the glass wall and there is a close up of his face from Grahams side of the glass. You can see that there is no reflection of Graham on it, thus meaning that there is no glass wall there in between Hannibal and Graham. This happens frequently through out the movie.
Continuity mistake: At the end, when Dolarhyde is holding Graham's son hostage, in alternating shots, the glass is in the kid's cheek, then in front of it.
Character mistake: At the very beginning of the film, when Hannibal Lecter is serving dinner to his guests, one diner asks "what is this divine looking amuse-bouche" when she and the other guests have a full plate of food. An amuse-bouche is a single bite of food meant to be served at the beginning of a meal, not a plate full of food. Lecter's guests would be better educated.
Other mistake: When Graham is about to pull out the top video case shelf at the Leeds' home, you can see the movie "Jaws" on the second shelf. "Jaws" didn't come out on home video until 1991.
Continuity mistake: In the scene right before Freddy Lounds is abducted by Dolarhyde, he is driving his car back to the garage of the newspaper he works for. In the scene of him pulling into the garage, he has half his arm hanging out of the rolled down window, then in the very next shot the window is rolled all the way up.
Continuity mistake: Jack gives Will a picture upside down, and places a shell on top of it, right in the center of the paper. From a different angle the shell is on the right side.
Continuity mistake: Toward the end of the movie, Will Graham is talking to Reba at the hospital, and you can see that he has a pimple over his right eye. When he goes out of the room, Crawford hands him Dolarhyde's journal, and the pimple is gone.
Continuity mistake: Anthony Hopkins starts the film with a conservative mid-Atlantic accent that requires no heavy acting. When he is talking to Will Graham in the cell phone, he changes to a ridiculously broad Georgia drawl, even when he isn't doing "funny voices." How he manages to fit either of these in as a Lithuanian of Italian descent is anyone's guess.
Character mistake: During the opening credits, one of the newspaper headlines reads "FBI Agent in Extremely Critical Condition". The story under the headline says that "local police found Dr. Hannibal Lecter fatally wounded in his Chandler Square residence", and that "the call was made by Special Agent Will Graham of the FBI". Neither was true since Lecter lived and Graham went unconscious after the stabbing.
Factual error: The dates of the two murders do not match any year of the 1980s. 25th of February occured on Saturday in 1984 and 1989, but the moon was not full on that particular day in 84 or 89.
Plot hole: When the FBI finds out that Dolarhyde knows where Graham lives, they send a chopper and some agents over to Graham's house to pick up his wife and son. His wife is startled by the noise of the chopper SUDDENLY appearing without any warning. How could she have not heard the chopper approaching or seen the light?
Factual error: Towards the middle of the movie there is a quick shot of a van driving down a road. To the right of the van on the side of the road is a solar cell that is powering a Department of Transportation device. This is the type of solar cell you see for the construction arrow signs on the side of the road telling you that you must merge. These weren't around in the 80's.
Other mistake: When Graham and the police are headed to Dolarhyde's house (after visiting Chromalux), you can see a billboard as the police car squeals around a corner. It's an H&R Block billboard saying: "It's your refund. Get it faster." Didn't this slogan just come out a couple of years ago?
Revealing mistake: When Will's wife shoots Dollarhyde at the end, watch closely when she shoots him for a second time and hits him in the cheek. For about one frame, you can see what looks like a wire coming out of his cheek that has caught some light, and about a half-second later, you can see some sort-of small brownish cap hit the floor on the right side of the screen. (It's very tiny so you have to look closely.) These types of effects are usually accomplished by putting a small prosthetic cap attached to a piece of wire over the bullet wound makeup, which is then pulled from off-screen to reveal the "bullet hole." It looks like both the wire and prosthetic cap both managed to get caught in the shot. (Slow motion or freeze-framing help but aren't required - both the wire and the cap are easy to catch once you see them the first time).
Factual error: When Will sees the bedroom covered in blood, the blood appears bright and fresh, despite the fact it had been sitting for several days and should have looked dark and coagulated.
Continuity mistake: In the first house, the camera pans toward the mirror. The doll leaning on it changes positions, leaving the crack hidden in the first place, and visible a fraction of a second later. The hair of the doll also changes, covering its forehead first, and combed later on.
Continuity mistake: In the first house Will visits, the first shot of the mirror shows a long drop of blood on the right, which becomes short in a following shot.
Revealing mistake: When Will stabs an arrow and shoots at Hannibal, a white vest underneath Hannibal's shirt is coming out on the right, to allow for the stunts.
Continuity mistake: Jack gives Will a picture, by placing it upside down on a table. The first close-up shows the table brightly lit, but from a new angle it's in the shade.
Answer: His choices had to do with the layout of peoples' property. At his job, he studied customers' family video tapes that contained scenes of their homes and yards. He looked for seclusion around the properties, easy-access back entrances, whether there was a family dog that would bark, and so on.
raywest ★
But what was his reason for killing them? Was it because he saw a happy family and he was angry because he never had one or because he saw a life that he would never have?
He chose the houses that had big backyards. During the Edward Norton/Lecter interaction, Lector says something about how blood looks in the moonlight.