Jack's Back is a 1988 thriller film (with some mild supernatural elements) directed by Rowdy Herrington and starring James Spader as a pair of Polar Opposite Twins with Twin Telepathy.
When a wave of Jack the Ripoff killings occurs in Southern California, a young, idealistic medical intern named John (Spader) begins attempting to play detective, suspecting a doctor... an investigation which ultimately leads to his untimely demise and his angsty, Troubled, but Cute, Darker and Edgier twin brother Rick (also Spader) taking the investigation into his own hands with the help of a criminal psychologist who takes on the role of The Profiler (Robert Picardo), ultimately leading to an abrupt, tense confrontation with the killer.
Tropes:
- Backup Twin: Rick
- Black Guy Dies First: The first person seen killed is a black Disposable Sex Worker.
- Break the Cutie: As if the twin in the second half of the movie hadn't been through enough already.
- Byronic Hero: The twin in the second half of the movie.
- Darker and Edgier: the second half of the movie, in contrast with its Lighter and Softer first half.
- Deadly Doctor: Dr. Sidney Tannerson is the real copycat killer.
- Decoy Protagonist: John, the twin in the first half of the movie appears to be the protagonist until he is murdered by Jack halfway through the movie.
- Decoy Antagonist: Due to Jack's behavior (plus his name) and him both killing John and attempting to kill Rick, we are led to believe that he is the copycat killer. He isn't.
- Disposable Sex Worker: A Jack the Ripoff is recreating the killings of Jack the Ripper. Naturally, all of his victims are prostitutes.
- Doomed Protagonist
- Groin Attack: After Jack fails to shoot rick with Rick's unloaded gun, Rick ends the fight by kicking Jack in the groin hard.
- Hoist by His Own Petard: Rick uses Sydney's own switchblade to kill him.
- Hollywood Glass Cutter: The Ripper breaks into Chris' house by using a glass cutter attached to a suction cup that cuts a perfect circle in the window pane.
- It Works Better with Bullets: During their fight, Jack grabs Rick's gun and attempts to shoot him with it, only for nothing to happen because the guy who sold it to him didn't sell him any bullets.
- Jack the Ripoff: The basic premise. 100 years after the Jack the Ripper murders, someone is replicating his crimes on the respective days of each victim's death.
- Meaningful Name: Subverted with Jack, who ultimately turns out not to be the murderer.
- Never Suicide: Jack strangles John and then makes it look like John hanged himself. the police buy this for a while, but John's brother Rick does not.
- Nice Guy: The twin in the first half of the movie is one of the friendliest, kindest, most thoughtful characters ever shown in a movie.
- Not Me This Time: After being arrested, Jack confesses to murdering John, but denies being the Ripper and killing the Disposable Sex workers. He is telling the truth.
- Polar Opposite Twins: A pure, Wide-Eyed Idealist Nice Guy, and his Cute but Troubled Anti-Hero twin brother.
- The Profiler: The psychologist played by Robert Picardo.
- The Reveal: Dr. Sydney Tannerson is the real killer.
- Supernatural Fiction: The story has a Dean Koontz-like thriller plot about a supernaturally gifted hero facing off against human evil, but the supernatural elements are relatively understated and only briefly alluded to.
- Troubled, but Cute: Rick is more aggressive twin, tends to get into trouble more, and obviously has had a lot of very dark things on his mind even before his brother's murder.
- Twin Telepathy: An important part of the twins' connection to one another.
- Vigilante Man: The second twin, by the end of the movie.
- Wide-Eyed Idealist: The main character in the first half of the movie is not only incredibly chipper and friendly, but also willing to shirk his duties as a medical intern if it means speaking out for the underprivileged and dispossessed.
