Steve Hodel says that after he learned that his father, Dr. George Hodel, was a suspect, at one time, in the mysterious 1947 murder of Elizabeth Short, known as “The Black Dahlia,” he started to investigate. Expecting to exonerate his father, Steve says he was shocked at the evidence he found which led him to believe that George did kill Short – and he says he believes his father may have killed other women as well.

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“I discovered that he’s a serial killer,” Steve says in the video above from Wednesday’s episode of Dr. Phil. “He was an extreme narcissist. He wanted to remain above the fold in the newspapers … He was pure evil.”

Dr. Robert Schug, a forensic psychologist and professor of criminology at Long Beach State University, weighs in on how the crime scene evidence suggests the type of person who would commit a murder like that of Short’s. And, he sheds light on whether George was a good fit for someone who might commit this type of murder.

WATCH: What Recordings Reveal About Possible Murderer Of 'The Black Dahlia'

On Wednesday, hear from George Hodel’s great-granddaughters whose top-ranked podcast, “Root of Evil: The True Story of the Hodel Family and the Black Dahlia,” is gripping the nation with never-before-heard archival audio of disturbing family secrets. Check here to see where you can watch.

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New Evidence Revealed For The First Time That May Indicate Who Murdered 'The Black Dahlia'