The episode, "Long Island Serial Killer," begins at 9 p.m. Friday, Sept. 8, and lasts until 11 p.m.
The suspect in the case, Rex Heuermann, age 59, resided with his wife and two children at the Massapequa Park home where he grew up at the time of his arrest in late July.
He's been charged with the killings of three women and is the prime suspect in a fourth murder.
The 20/20 episode, anchored by Deborah Roberts, focuses on the investigation and also features interviews with family members of victims and key players in the cases.
In addition, portions of an interview by a YouTuber with Heuermann at the suspect's Fifth Avenue office in Manhattan are also included during the episode.
Click here to view a preview of the episode.
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