Sea of Love (1990)

Troubled New York City detective Frank Keller (Al Pacino) investigates a serial killer who finds victims using personal ads in a magazine and leaves the song "Sea of Love" playing at his crime scenes. With the help of his partner, Sherman Touhey (John Goodman), Frank concocts a plan to find the killer using his own personal ads. But when Frank falls for one of his chief suspects, Helen Cruger (Ellen Barkin), he struggles to reconcile his personal life and his professional duty.