On Dr. Oz’s “True Crime Tuesday,” the youngest victim of the Golden State Killer opened up about how she used her knowledge of the case to disarm him.

Margaret Wardlow was just 13 when the alleged Golden State Killer, Joseph James DeAngelo, creeped into her Sacramento home in 1977 and stood over her bed at 2 a.m. After he blindfolded her and tied her up, he did the same thing to her mother. Wardlow told Oz that she had been “obsessed” with the previous news stories about the notorious rapist killer well before he crept into her room.

“I don’t remember being scared so much. I just remember thinking, you know. I’m not going to let him have what he wants,” Wardlow said.

CrimeOnline‘s Nancy Grace, who joined Dr. Oz to discuss the case, added that Wardlow had to be in shock. Wardlow said she knew he wanted to frighten her and she tried to keep the situation at bay by not showing fear.

“I knew he was there to frighten me. I knew he got off on the fear of his victims and you know, he threatened me, constantly….’Do you want to die? Do you want me to kill your mother?’ And as a teenage girl I just told him, I don’t care. I really replied, I don’t care. And I really thought at that time this is, he’s not going to get what he wants. He’s mostly likely going to leave sooner rather than later if he doesn’t have me in this fear that he’s trying to provoke.”

Guests on Dr. Oz’s “True Crime Tuesday” also include Detective Paul Holes, the investigator who cracked the case with the help of DNA kits, and another victim, Jane Carson- Sandler, who discusses how emotionally difficult it was to see the alleged killer in court.

Watch the full story on Dr. Oz’s “True Crime Tuesday” on ABC, on September 25. Check local listings for air times.

[Feature Photo: Margaret Wardlow/SONY Pictures Television screenshot]