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Crime News Snapped

Woman Doses Friend With Ketamine Before Killing Her, Stealing Credit Card To Pay Off Debts

Authorities theorized that after Marian Parsons turned down her friend, Debra Henderson, for another loan, Henderson put ketamine in her coffee and killed her.

By Benjamin H. Smith

Some friendships happen fast, as if you have known someone your entire life and were just waiting to meet them. That’s what happened with Marian Parsons and Debra Henderson, two women in their early 50s who helped each other overcome loneliness and boredom.

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Unfortunately, their friendship couldn't overcome gambling debts, jealousy, and murder.    

Marian grew up in a family of four children in Oklahoma, and as a young woman, she married Bill Parsons, who was 20 years her senior.

“Bill was very well-set, so he took care of everything for her,” friend Becky Brock told “Snapped," airing Sundays at 6/5c on Oxygen.

Bill and Marian spent several decades together, but they never had children. As her husband became a senior, Marian wanted more out of life, and they later divorced. The former couple remained friends, however, and she came out of the marriage financially independent. 

“There was a house that they sold, and the profits gained from the house was sufficient that Marian Parsons didn’t need to work. She was able to live off that as well as other investments that she had,” former Assistant Prosecutor Ricky Sipes told producers

Now in her early 50s, Marian began dating again, and she soon met a man named Robert Sterling through an online dating service. She eventually moved to be near him in Palmer, Texas, a small town about 30 miles south of Dallas with a population of just over 2,000. 

Marian got her own place in nearby Waxahachie and tried to make friends.

“Marian was a good person. She was always laughing, always in a good mood. Never had anything bad to say about anybody,” Brock told “Snapped.”

After dating for a year, Marian decided to move in with Sterling, but she felt lonely and isolated in Palmer. She found some solace in her new friendship with Debra, who lived on the property next to Sterling’s and ran cattle.

Debra had grown up in a big family of migrant farm workers in Austin, Texas. Her first marriage resulted in two boys, and she subsequently married Bobby Henderson, a long haul trucker. But after 20 years of marriage, Debra’s kids had moved away, and she was experiencing empty nest syndrome. She and Marian became fast friends and socialized with their husbands when Bob wasn’t out on the road for work. 

Just a month after moving in with Sterling, Marian went missing. Sterling notified the Ellis County Sheriff’s Office on Dec. 3, 2010, saying he hadn’t seen her in two days. He said their relationship had hit a rough patch, and he thought she might have gone to stay with a friend, according to court documents

Sterling claimed he had last seen Marian on the morning of Dec. 1.

“He said that she was going to go to breakfast with the neighbor,” former Ellis County Sheriff’s Corporal R.D. White said.

That neighbor was Debra.

Investigators spoke to Debra, who said she had breakfast with Marian at an IHOP before they went their separate ways. Debra also said Marian was having second thoughts about her relationship with Sterling. 

“Debra had indicated that the relationship between Marian Parsons and Robert Sterling was a bit contentious, and Marian Parsons was talking about returning to Oklahoma,” White told “Snapped.”  

Marian Parsons Spd 2807

Authorities wondered if Marian had another man on the side or was hiding from Sterling, but they uncovered no leads confirming those suspicions. They then spoke to her family, who had no knowledge of her whereabouts.

Bill, however, said that he had spoken to his ex-wife on the afternoon of Dec. 1, and that she told him she was going to help Debra retrieve an ATV that was stuck in a pasture, according to court documents.

In reviewing Marian's finances, detectives found charges on her bank cards that had been made after she went missing. On Dec. 3, someone had tried to withdraw money from her bank account. 

“The card was denied at the ATM because of not knowing the PIN number,” Sipes told “Snapped.”

Reviewing the security footage, investigators saw Debra at the ATM trying to make the withdrawal. She was brought in for questioning, and she admitted to investigators that she and her husband were having money troubles.

Marian had previously lent Debra $2,700 in October 2010, according to the Waxahachie Daily Light newspaper. Now, Debra claimed she had stolen Marian's debit card following their breakfast on Dec. 1. Investigators asked her to take a polygraph, to which she agreed. 

Days before her test was to take place, Bobby called police and told them he had just been robbed by his wife. He said Debra had a gambling problem and incurred huge debts that he had only recently become aware of.  

“Bobby said, ‘The money that I’ve put up in the safe for our property taxes is gone. The man that we’re buying the property from has called me and told me that we’re three months behind in our land payments,’” White told producers.

Bobby ultimately decided not to pursue criminal charges against his wife, and in the meantime, Debra failed her polygraph test. While she insisted she had nothing to do with Marian’s disappearance, investigators obtained a warrant for her arrest on credit card fraud, but they decided to wait to execute it until they concluded their murder investigation. 

On March 19, 2011, Bobby called the Ellis County Sheriff's Office and told them he found a human skull on his property. During a search of the area, authorities discovered Marian's remains buried under a large heavy sheet of metal that was covered with cement blocks, trash, and old tires. 

Divers also recovered a 9mm handgun from a pond on the property. It had been purchased by Bobby and reported stolen by Debra in April 2010 during what she claimed was a home invasion robbery, according to the Waxahachie Daily Light. 

Debra was then taken into custody and initially charged with credit card abuse, according to Dallas ABC affiliate WFAAUnder questioning, Debra began crying and claimed she had accidentally killed Marian.

“She had some kind of attack or something. I don’t know. I don’t know what happened,” she claimed tearfully in her video interrogation obtained by “Snapped." “She grabbed my arm, and she fell out of the buggy and ... I ran over her.”

When asked how exactly she ran over Marian, Debra’s details were vague. When asked why she didn’t call 911, she had no answer.  

“I did panic. I didn’t know what else to do. And I pulled her down there, and I covered her up. I didn’t know what else to do. I killed somebody,” she said. 

Debra Henderson Spd 2807

Investigators went back to the Henderson ranch and reenacted the crash as Debra described it. It made no sense.  

“She wouldn’t have fallen out the way that Debra described of how she ran her over. The story that Debra gave and the evidence that we found did not match up,” Ellis County Sheriff's Office crime scene technician Krista Jeffrey told producers.

Marian’s remains had been scavenged by animals, but the medical examiner found multiple broken bones, which was consistent with Debra’s account. They also found two small abdominal wounds, however, which could have been caused by a knife or bullet.

Toxicology tests revealed large levels of ketamine, an animal tranquilizer. The cause of death was determined to be homicide, but the means of death was unknown due to the decomposition, according to court documents

At Debra’s trial in May 2012, prosecutors put forth the theory that she killed Marian after being turned down for a second loan.

“She probably put ketamine in her coffee at that time. That's a tranquilizer for general use for horses, and Debra had horses,” White told “Snapped.” 

In her defense, Debra stuck to her story of accidentally running Marian over, hoping to catch a manslaughter sentence instead of murder.  

On May 17, 2012, after deliberating for less than four hours, a jury found Debra guilty of the murder of Marian, according to the Waxahachie Daily Light. She was also found guilty of three counts of credit card abuse and sentenced to life in prison, reported the outlet

Debra will be eligible for parole in 2042, according to the Texas Department of Criminal Justice, at which time she will be 84 years old. 

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