"I can't ever remember a time when he wasn't beating us," her son Randy recalled
Credit: Courtesy Wendy Maldonado

After spending nearly 10 years in an Oregon state prison for murdering her husband, there’s one question Wendy Maldonado still can’t answer.

“I just don’t know why that night,” Wendy, 46, tells PEOPLE when asked why – after years of relentless, sadistic abuse at the hands of her husband – she finally decided to kill Aaron Maldonado in the early morning hours of May 1, 2005. “I don’t know if I’ll ever have an answer about why it happened on that night.”

Wendy is sure of one thing, however: She had to kill her husband before he killed her – and her four sons, she says.

That morning, Wendy and her then-16-year-old son Randy, slipped into her sleeping husband’s bedroom and crushed his skull with a hatchet and a hammer.

“If I hadn’t done this,” says Wendy, “I know we’d all be dead by now.”

Instead, she got sentenced to 10 years in prison by a judge who described the brutality that she and her sons endured as “the worst case of domestic violence that any of us has seen.” (Randy was sentenced to 75 months.)

For more on the abuse endured by Wendy Maldonado and her ultimate decision to murder her husband, pick up this week’s issue of PEOPLE on newsstands

Aaron and Wendy met in high school in Grants Pass, Oregon. She married him at 17 and the abuse started shortly after. She claims he knocked out 17 of her teeth, burnt her with white-hot coat hangers and repeatedly strangled her until she blacked out, among other forms of abuse.

Her sons were also brutalized. “I can’t ever remember a time when he wasn’t beating us,” recalls Randy, who says his father would regularly “punch us in the face” without the slightest provocation.

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Wendy wanted to leave him, but Aaron “repeatedly threatened” to kill her and their sons if she ever tried, graphically detailing exactly how he would do it, she says.

“He told me that every day and that’s what I believed. And I still believe it,” says Wendy, who will be released from Oregon’s Coffee Creek Correctional Facility in March 2016. “I still believe it.”