Sea of Love (1989)
Frank Keller is a New York detective investigating a case of a serial killer who finds the victims through the lonely hearts column in newspapers. Keller falls in love with Helen, the main suspect in the case.
In Manhattan, Detective Frank Keller is an efficient and veteran cop with twenty years on the force, who is lonely and misses his ex-wife Denise. She left him to live with his colleague from the same precinct Gruber. When a killer kills his victim with a shot on the neck and leaves a single playing "Sea of Love", Frank is in charge of the investigation. Detective Sherman, from a district outside Manhattan, joins Frank when a second victim is killed in the same MO. They find that both victims have written poetry in the lonely hearts column of the single magazine "New York Weekly". When there is a third case, Frank convinces his chief to write for the magazine and work undercover investigating the women that reply the advertisement. Frank falls in love for the prime suspect, the manager of a shoe store Helen Cruger, jeopardizing his investigation.
Seen-it-all New York detective Frank Keller is unsettled - he has done twenty years on the force and could retire, and he hasn't come to terms with his wife leaving him for a colleague. Joining up with an officer from another part of town to investigate a series of murders linked by the lonely hearts columns he finds he is getting seriously and possibly dangerously involved with Helen, one of the main suspects.
A detective investigating a series of murders becomes involved with a woman who may be the culprit.
- New York Police detective Frank Keller (Al Pacino) investigates the murder of a man in Manhattan, shot dead while face down naked in his bed while listening to a 45rpm recording of "Sea of Love". Keller has three clues - a lipstick-smeared cigarette, a wanted ad the dead man placed in a newspaper and a perfect set of fingerprints. Immediate suspicion falls on a vengeful woman who answered his lonely hearts personal advertisement.
A second man dies in the same manner in Queens. Detective Sherman Touhey (John Goodman) suggests they collaborate. Both victims had put rhyming ads in the paper. They track down Raymond Brown (Michael O'Neill), the only other man with a rhyming ad. He's a married man and admits placing the ad, but swears on his children's lives that he threw away all the letters and never saw anyone.
Keller has an idea - place their own rhyming ad in the paper, take any women who respond to a restaurant and take the prints from their glasses. Keller's boss (John Spencer) thinks it is a bad idea. However, Brown soon turns up dead.
Keller has dinner with several women, while Sherman posing as a waiter puts their empty glasses into evidence bags. One of the women, Helen Cruger (Ellen Barkin) snubs Keller and leaves before she takes a drink. Keller bumps into her again at a market, but this time, Cruger is more friendly. Keller goes back to Cruger's place, ostensibly to get her fingerprints. He panics when he finds a gun in her purse, but it turns up to be just a starting pistol.
Keller and Cruger begin a serious relationship. Keller has a chance to obtain Cruger's fingerprints on a glass, but decides to wipe the glass clean. Their relationship proves rocky when Cruger discovers that Keller is a cop.
Cruger's ex-husband Terry (Michael Rooker) breaks into Keller's apartment and threatens him with a gun. He makes Keller lie on his bed and show him how he made love to Helen, just as he had done with his ex-wife's other three boyfriends. Keller overpowers Terry and tries to call the police, but the killer is wild and lunges at him. In the struggle, Terry is accidentally thrown through the window and plunges to his death.
Keller and Cruger reunite. She forgives him, and they resume their relationship.