The Poughkeepsie Tapes

Filmed in a documentary style complete with Jittercam, The Poughkeepsie Tapes is a movie that is best seen with the lights on. It chronicles the (fortunately fictional) spree of killings in Poughkeepsie, New York, that are all videotaped by the killer, who comes to be known as the Water Street Butcher. Hilarity, Gorn, gambits, terror and ham ensues.

Tropes used in The Poughkeepsie Tapes include:

Adult Fear: After this movie you'll likely never help out strangers on the road or let your kids play on the front lawn or fundraise door-to-door.
Anticlimax: Around three-fourths of the way through the movie, the police claim that they've captured the killer. They're wrong.
Apologetic Attacker: Cheryl, who is forced to slit a woman's throat.
Ax Crazy: The killer.
Being Tortured Makes You Evil: A straightforward example of this trope.
Being Watched: Cheryl can feel the murderer watching her immediately before her kidnapping.
Confusion Fu: The Water Street Butcher switches up his M.O. often and even within these different phases demonstrates odd inconsistencies. This is part of what makes him so hard to catch, since it makes him nearly impossible to profile and difficult to realize it's the same culprit.
Downer Ending: He gets away.
Frame-Up: The Water Street Butcher successfully frames a former cop, who ends up being executed.
Genre Savvy: Right before getting kidnapped, Cheryl tells her friend on the phone that she feels like she's been being watched and that something bad is about to happen to her.
Gorn: Not as much as some horror movies, but definitely noticeable.
Infant Immortality: Subverted to hell and back. The killer's murderous rampage begins when he kills a young girl by bashing her head in with the camera, and it gets worse from there.
- Played straight with the girl scouts. Although, he was going to kill them before Cheryl intervened.
Irony: The killer kills a cop using the justice system.
Jittercam: In many of the scenes, the killer is holding the camera.
Keep Circulating the Tapes: The film is only available a bootleg since MGM shelved the film due their financial issues (a release date was planned for February 2008 and trailers had come out in November 2007). The bootleg is also from a rough cut of the film shown at festivals as the directors never got to finish the final cut.
Large Ham: The Water Street Butcher has a flair for the theatrical and tends to wear a beaked Carnival mask with a ruffed cape. There's also the infamous manner in which he kills the English woman--he creeps up on her on all fours (actually using his feet as opposed to his knees for maximum effect) despite nobody being able to see but the camera, then slowly lances her through the neck.
Madness Mantra: "Just take me home, just take me home..."
Magnificent Bastard: One police officer actually acknowledges the possibility of admiring such a skilled and elusive killer in an interview and after a moment of hesitation firmly asserts that she could never feel anything but loathing for him.
Mockumentary: A rare case where a horror movie mockumentary tries to look like an actual documentary rather than simply shaky cam.
Nothing Is Scarier: You never see the killer's face.
Police Are Useless: So much that they execute one of their own for the crimes of the Water Street Butcher.
Scarpia Ultimatum: Subverted. He offers the English woman the chance to live if she lets him rape her. She agrees, but he immediately says he's not that stupid, and that neither of them would want her alive to see what he planned to do to her.
Shout-Out: The first chapter is titled "First Blood".
Stockholm Syndrome: Poor, poor Cheryl.
Stylistic Suck: The efficacy of the horror is subjective, of course, but the film is absolutely awful as a documentary, with weird editing and transitions and lots of uneventful footage that could be trimmed. As noted above in Keep Circulating the Tapes, the only available version of the movie is a rough cut, so the hypothetical final cut might've been better.
Torture Cellar: A basement serves as the killer's lair, but it's noticeably corpse-free.
Very Loosely Based on a True Story: The story is similar the crimes of real-life serial killers Roy Norris and Lawrence Bittaker, who in the late '70s and early '80s kidnapped five young women and sound-recorded the girls' screams while torturing them with a pair of pliers and a wire hanger.