FX: The Series - Season 1 - Eps 16: Gemini
When Leo sees disturbing similarities between the science fiction movie for which Rollie is providing the special effects, he begins to suspect the movie's director is a serial killer who terrorized Central Park four years ago and was never caught. He talks Rollie into using FX to get him to confess, but they soon discover the director has a dual personality and his murderous ""other"" is now taking over, ready to kill again.
About FX: The Series

Title: FX: The Series
First Air Date: 1996-09-09
Last Air Date: 1998-05-25
Status: Ended
Rating: 6.2/10 (from 16 votes)
Language: EN
Seasons: 2
Total Episodes: 40
Network: CTV
Genres: Drama
Production Companies: Unknown
Synopsis
Rollie Tyler, a special effects expert, helps his detective friend solve crimes by making criminals see what they want to see. But what is real and what is illusion?
Cast

Cameron Daddo
Roland 'Rollie' Tyler

Christina Cox
Angela 'Angie' Ramirez

Richard Waugh
Captain Marvin Van Duran

Jason Blicker
Detective Francis Gatti

Jacqueline Torres
Detective Mira Sanchez