Charles Manson's granddaughter reveals moment she discovered dark family secret: 'It was devastating'

In 2022, Sophia Maddox received a phone call that upended everything she thought she knew about her family — and sent her searching for answers about one of America's most notorious criminals.

At the time, the 22-year-old aspiring filmmaker and actress was living in Los Angeles, juggling odd jobs to make rent, while her father, Daniel Arguelles, was searching for answers about his own past.

Raised by his mother and stepfather, Arguelles had been trying to identify his biological father when he called Maddox with a startling discovery.

"He told me he thinks he found out who his father is, and if it's true, it's really dark," Maddox told Fox News Digital.

"He wasn't sure if I was ready to know.

And my dad is not a dark person.

He never taught me any dark things.

So if he says it's dark, my first thought is it must be famously dark.

So I asked him to just get it out of the way." WOMAN BRANDED ‘FEMALE CHARLES MANSON’ ESCAPED PRISON; PROSECUTOR NOW DOUBTS HER CONVICTION "'Is it Ted Bundy?'" she recalled.

"He said, 'Bigger.

Think of the biggest movie you know and the biggest director you know.' And I thought of the movie 'Once Upon a Time... in Hollywood.' I was trying to remember the name mentioned in the film.

And then I realized who it was: Charles Manson." Maddox immediately Googled Manson's name.

The resemblance, she said, was uncanny.

"I thought to myself, 'That's my dad,'" Maddox said.