An unsolved cold case spanning more than four decades has left questions in the minds of family and friends who knew Deborah Sue Agnew Williamson. 

Just two months after she was married in the summer of 1975, Debbie Sue was stabbed to death outside her South Lubbock home. Now family are pressing the police for answers in the search for closure. 

Liz Flatt was just a child when her older sister, Debbie, was killed outside of their home. In the last year, she started searching, at first just to learn more about who her sister was, but it turned into a desperate need for answers.

The biggest question being, ‘Who killed Debbie Sue?’

“She was young, full of life, she was just an extremely kind soul. She just befriended just about anyone,” said Flatt. 

Flatt wanted to collect memories of her older sister’s short life but it turned into a quest for answers.

“It just became a very empty hole in my heart, so I desperately wanted that,” said Flatt. “Then it turned into, I wanted her murder to be investigated again.” 
The Lubbock Police Department has had an investigator dedicated to this case since it happened in 1975, but can often run into problems when handling a 42 year old cold case. 

“If we’re dealing with a significant amount of time, people associated with that case, they may move off, they may become deceased so you lose info that you have available at the beginning of the case,” said Sgt. Marc Wall of the Lubbock Police Department. “So what they want to do is create gaps in the case so that they can find areas to work.”

Her family believes Debbie Sue knew her killer since it seemed like a personal attack.

“I really want to know why,” said Flatt. “It was obviously personal and someone that knew her. My mother is getting very elderly. I don’t know how much time she has left with me and I would do anything to give that to her.”

Debbie’s husband Doug was the one who found her that night but his alibi checked out. He was at work at the time of the murder. 

In the mid 80’s, Debbie’s family thought they finally had their answer. A man named Henry Lee Lucas confessed to the murder, along with several other murders across the country. But his accounts of what happened never quite added up. 

“They showed them the confession and it was immediate at that moment, they told them, he didn’t kill her, the confession was completely wrong,” said Flatt. The family was back to square one. 

Debbie Sue’s vicious murder doesn’t just haunt her family. Many friends of hers and people living in Lubbock during the time of the murder still remember that night and the headlines that covered the front pages for weeks.

“It’s been hard, I’ve always hoped that I would know who did this. I always joked around that when I went to heaven, I wouldn’t ask ‘Are there aliens?’ or ‘Who killed JFK?’ I was going to ask, ‘Who killed Debbie,'” said Mark Holmes, one of Debbie’s closest friends before her murder. 

Holmes worked with Debbie and her husband at a McDonald’s in town.  

“They said her name and I was in shock,” Holmes said. “I remember pulling my boot off and throwing it across the room. It really affected me badly.”

Police are hoping someone out there has a tip that can break this case open. And it starts with someone coming forward with new information. 

“If somebody knows something, it begins to kind of eat at them,” said Sgt. Marc Wall. “They may feel some conviction about what they know or any involvement they have. So as they’re separated themselves from that event over time, they may be more willing to speak to us.” 

And although it’s been 42 years since Debbie was murdered, her family is optimistic her killer will be caught. 

“I won’t ever lose hope. That’s something no one can take from me,” said Flatt. 

Recently, a non-profit called the Cold Case Foundation has agreed to take on the case. The team of retired investigators will hopefully find a new lead. 

But they’re asking for you help. If you know anything that might be important to this case, call the crime line at 741-1000 to help give justice to Debbie Sue, 42 years later. 

(Video to follow. Please check back later.)