(SACRAMENTO) -- When Margaret Wardlow recalls her childhood in Sacramento, California, she divides it into two distinct time frames.
There's the Sacramento before 1977, which she described as "a beautiful place" where she took hikes with her beloved golden retriever along the American River, a community where "I totally felt safe."
Then there's the Sacramento after 1977 when a serial rapist was on the loose -- and she became his youngest victim.
"As soon as the Sacramento Sheriff's Department came out and announced that we had a serial rapist that was attacking in Sacramento, everything changed," Wardlow tells ABC News' "20/20" in an interview to air Friday night. "People were on edge."
At the age of 13, she read anything she could get her hands on about the attacker, she said.
"I remember distinctly reading over one article three times and saying to myself, 'There aren't any more words that you haven't read,'" she said.
"I had a total obsession," she added. "I don't think I was the only person that was curious as to what was making this guy tick. And it was very clear that during the attacks he was using this fear that he was controlling people with, you know, by making them very much afraid of what he was saying to them and what he was doing to them."
Her mother convinced her she was too young to become a victim of the serial menace then known as the "East Side Rapist" and later as the "Golden State Killer."
"She definitely believed that we just weren't, like, on the radar of this guy," she said.
But on Nov. 10, 1977, her life would be changed forever when at 2 a.m., she woke up to find the attacker wearing a mask and leather gloves standing at her bedside, the blinding light of his flashlight in her eyes.
At first, she said she thought her mom and a neighbor friend were playing a practical joke. Then in a "harsh whisper" the intruder told her, "'This isn't a joke.'"
"And I knew at that moment, this is not my neighbor, Bill," she said. "This is the 'East Area Rapist' most likely. And he's in my home."
She said he tied her up and blindfolded her. He did the same to her mother in an adjacent bedroom and stacked plates on her mom's back. Having already read of the attacker's modus operandi, she knew he listened for the rattling of the plates to tell him that the victim was trying to get away.
She recalled that as she laid there bound, "a little voice inside of me said, you know, 'You get out of a lot of stuff, Margaret. But you're not gonna get out of this one. And just you need to understand that this is what's gonna happen to you. You're gonna get raped. But you're gonna be OK. And he's not gonna hurt me.'"
She had every reason to be afraid. She said the attacker repeatedly threatened to kill her and her mother, and once during the episode held a knife to her.
But having read so much about the attacker, she said she felt she "had the advantage."
"How many rape victims in this sort of situation with an unknown attacker have a dossier written about their attacker?" she said.
"My instinct said, 'Don't let him see you sweat,'" she said.
Every time he threatened to kill her or her mother, she defiantly told him, "I don't care."
"It was the best answer I could come up with in order to, like, let him know, 'I'm not afraid of you,'" Wardlow said. "He wants fear. And I knew that. So, I just told him, 'I don't care.'"
She said she was briefly sodomized during the attack, but the rapist seemed to give in to her defiance.
"He wasn't getting what he wanted," she said. "He wanted fear. He wanted to see fear in me."
She said he eventually fled the scene, sparing her and her mother.
Wardlow, now 53 and married with a daughter of her own, said she realizes she was "extremely lucky."
"I think it was a combination, perhaps, of my age and my innocence that he realized once he was there," she said.
Police said that in the two decades after Wardlow was attacked, the "Golden State Killer" would roam California killing 12 people and raping more than 50 women.
On April 24, the Sacramento County Sheriff's Department announced there had been an arrest in the cold case. Joseph DeAngelo, a 72-year-old retired cop living in the Sacramento suburb of Citrus Heights, was identified through a DNA evidence as the suspected "Golden State Killer."
Wardlow said a retired Sacramento County Sheriff's deputy called her the night before DeAngelo's arrest was publicly announced and told her the news.
"I was elated. I could not believe it," she said, adding that it was "the most beautiful, beautiful phone call I've ever had. I mean, I was just so excited."
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