"He's just got a dark, dark, dark soul." The movie shows how Alcala would lure his victims by posing as a professional photographer.
Detectives say he would toy with his victims, often strangling them and allowing them to regain consciousness before finally killing them.
After killing them, Alcala placed their bodies in grotesque poses, sometimes photographing them.
On Tuesday, prosecutors said Alcala is responsible for the murder of 28-year-old Texas native Christine Ruth Thornton.
Alcala met Thornton in San Antonio around August 1977 and then allegedly dumped her body on a ranch in Granger, Wyoming. “All of this was before the 1978 appearance on ,” Sweetwater County and Prosecuting Attorney Danny Erramouspe tells PEOPLE.
But unbeknown to her, the show's producers and the millions of viewers tuned in at home, the smiling photographer had already murdered two women and would go on to rape and mutilate four more and a 12-year-old girl.‘I want to thank the family and friends of the two victims for their eloquent statements,’ Manhattan Supreme Court Justice Bonnie Wittner told the courtroom, which was packed with friends and family of Crilley and Hover.‘This kind of case is the kind I've never experienced and hope to never again,’ Wittner said before turning away from her microphone and breaking into tears for a few seconds.
‘Sorry,’ the judge said as she gathered herself to continue.
Now, the disturbing story is being made into a movie,, which premieres Sunday on Investigation Discovery.