When Karlsen was jailed, Erin said she went to visit her father and told him that she knew he was involved in her mother's and Levi's deaths.
"He won't ever own up to Levi," Erin said. "But he did tell me… 'It's been over 20 years, and they still haven't got me yet. What makes you think they're going to get me now?"
While she said she isn't angry with her father, Erin said she regrets not going to police sooner with her suspicions of her mother's death.
"What if I had said something earlier?" Erin said. "Maybe he'd still be here for his girls."
When Karlsen faces trial in two weeks, a judge ruled that testimony about the California fire and Christina Karlsen's death is off limits.
"I want him to look me in my eye and tell me exactly what he did," Erin said.
"Then I want him to go away for the rest of forever."