The family of a North Carolina woman who was fatally stabbed to death by her husband who claimed he had taken too much cold medicine last year broke their silence about their anguish.

In the early morning hours on Sept. 1, 2017, Matthew Phelps called 911 and told dispatchers he thought he killed his 29-year-old wife Lauren while in a haze after taking cold medicine. Phelps, now 30, eventually pleaded guilty to first-degree murder and, on Oct. 5, he was sentenced to life in prison.

On Wednesday, Lauren’s parents Dale and Laurie Hugelmaier spoke with ABC’s Good Morning America about domestic violence and the warning signs they wish they had discussed with their daughter in the days before her death.

“I think about it every day. What I did wrong. What I missed. ‘Til this day I just regret not knowing or keeping my eyes open and watching,” Dale Hugelmaier said. “I just took everything as is.”

The couple had been married for 10 months and lived in Raleigh, North Carolina. Lauren was a Sunday school teacher and Matthew was studying to be a pastor, a friend told ABC.

Lauren Hugelmaier Phelps. Facebook

But the marriage was far from idyllic. In documents used to obtain seven search warrants after the murder, Lauren was “preparing to end the relationship.”

Investigators revealed that tensions had allegedly erupted between the couple over finances; that Phelps allegedly “was spending more money than the couple made”; and that Lauren allegedly “had recently taken drastic steps to limit her husband’s spending,” according to The News & Observer‘s review of those documents.

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In Wednesday’s television interview, Lauren’s sister Beth Agner said she spoke to her sister hours before she died. Lauren told her she was prepared to leave him because he was allegedly cheating on her.

“I think that he made a decision that day that Lauren was not gonna leave him, even if that meant he had to kill her,” Agner told ABC. “The police called him a monster. And we’re talking about homicide detectives who see homicides every day.”

An autopsy showed that Lauren suffered 123 cuts and stab wounds in the attack at the couple’s two-bedroom townhouse.

Lauren’s mother broke down in tears while talking about how her daughter died.

“She was laying on her stomach on the floor. He was sitting on her back stabbing her,” she said during the interview.

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When Phelps pleaded guilty, he apologized for his actions.

“I feel like a monster, one of the wretched, a part of the darkness we don’t speak of,” he said during his hearing. “That darkness consumed me until I was blind to the path I had taken and deaf to my own cries for help.”

Lauren’s father Dale says he will never forgive Phelps.

“He planned the whole thing from the get-go in my opinion, right from day one to the end,” he said. When asked if he’d forgiven Phelps, he added, “Never. I mean, I’ll take him to my grave. And I’ll still hate him.”

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