Elderly Man’s Death Linked To Bizarre Murder Plot And Love Triangle Involving Twin Sisters

On April 1, 1990, EMTs in Lemmon, South Dakota raced to respond to a medical emergency. A 911 call was made by 45-year-old Darlene Phillips about her ex-husband, Walter Gibbs. 

First responders performed CPR, but Gibbs, 85, was pronounced dead upon arrival at the local hospital. Based on his age and significant heart history, the cause of death was believed to be natural and attributed to a probable heart attack.

“Since there was no foul play suspected, no autopsy was performed,” Shane Penfield, Perkins County State’s Attorney, explained to “Exhumed: Killer Revealed,” airing Sundays at 7/6c on Oxygen.

The community mourned the loss of the well-liked Gibbs, who’d married five times. By locals’ accounts, he maintained a particularly tight bond with Darlene, who he'd married and divorced twice. Though they were no longer husband and wife, Darlene was living with Gibbs and caring for him for about the final year of his life. Her twin sister, Delores Christenson, also moved in to help. 

But investigators learned something surprising: Delores, like her twin, also had wed and divorced Gibbs twice. The three remained inextricably tied to each others’ lives.

Despite their sometimes turbulent relationships, Gibbs still cared for the twins. He was content to let them live in his house, according to “Exhumed: Killer Revealed.”

Walter Gibbs

But months later, information came in that made them rethink the Gibbs case.

On December 8, 1990, Robert Overturf, Fmr. Special Agent, South Dakota Attorney General, received a call concerning a woman incarcerated for murder in a penitentiary in Springfield. The woman reported that a fellow inmate, Darlene Phillips, who was serving a sentence for arson, confided that she had murdered Gibbs. 

Investigators also learned that there was another person in the picture. Darlene’s husband, Jerome “Jerry” Phillips, then 38, a convicted sheep rustler, was also living with Gibbs at the time of his death. Trouble brewed in the household shortly after Jerry arrived there. Jerry was soon tired of taking care of Gibbs, according to "Exhumed."

“According to Darlene,” Penfield told producers, “Delores and Jerry had a plan.”

Their scheme allegedly involved increasing the dosage of nitroglycerin and spiking Gibbs’ Milk of Magnesia with sleeping pills. When that plan failed to produce results, she said Delores and Jerry “had to step it up,” according to Rapid City Journal crime reporter Ron Brown.

Darlene said she’d overheard Delores and Jerry discussing smothering Gibbs with a pillow to expedite things. 

On April 1, 1990, the plan was carried out in Gibbs’ living room. To investigators’ shock, Darlene admitted that she held Gibbs’ arms down when he was smothered by Jerry.

“Darlene told me she was an unwilling participant,” said Overturf, adding that Jerry “forced her to do it.”

The motive for the murder? Financial gain. The plan included having Gibbs change his will to make Delores the primary beneficiary instead of cousins in Nebraska. The twins and Jerry would then reap the spoils.

James Hartwell, who witnessed the change in the will, told investigators that “didn’t feel comfortable” about what was happening. But Hartwell reluctantly signed the document. Gibbs’ death 10 weeks after the will was revised didn’t sit right with him. Hartwell said he’d protest his signature if Gibbs died by anything other than natural causes.

Investigators dug deeper into the twins’ history.  Locally they were known as being “odd,” according to Overturf. They had had various scrapes with the law and were known for starting fires. But could their criminality include murder?

Overturf interviewed Delores for her side of the story. At the time he questioned her she was incarcerated on a cattle rustling charge. She was given her Miranda rights and agreed to speak, according to “Exhumed: Killer Revealed.”

Delores admitted there was a plot to kill Gibbs, but her version of the events didn’t match her sister’s account. She said she stayed out of the room where the homicide happened and that Darlene’s involvement wasn’t coerced.

“Delores tried to minimize her part,” said Penfield. 

As the twins pointed the finger at each other, detectives learned more about dynamics of their complicated relationship with each other and Jerry. Although Jerry was married to Darlene, he was in love with Delores, according to “Exhumed: Killer Revealed.” 

Overturf interviewed Jerry for his side of the story, and he offered another version of the events.

“Jerry had expressed that Walter didn't want to live anymore,” investigators said. He suggested that Gibbs’ final moments was an assisted suicide.

Jerry said Darlene had wanted the death to happen and wasn’t forced to hold Gibbs’ arms while he placed the pillow over his face, investigators told producers. He also confirmed that Delores was in the kitchen when the events went down.

Darlene, Delores, and Jerry were indicted for murder and conspiracy charges. But to secure a conviction, agents need to be able to prove how Gibbs actually died. To do that, Gibbs’ body would have to be exhumed.

On May 6, 1991, 13 months after his burial, Gibbs was exhumed. An autopsy found white pellets in Gibbs’ stomach. Toxicology results identified the white substance in his stomach as diphenhydramine, which is commonly used in sleeping pills. 

"Finding those pills ended up being forensic proof this murder did occur,” said Penfield.

The manner of death was changed to homicide and officials moved with murder charges against all three suspects. 

Jerry sought legal advice and pleaded guilty to conspiracy to commit second-degree murder. He was sentenced to 50 years.

On June 3, 1991, the twins went on trial for first-degree murder.  Jerry testified for the prosecution at the twins' trial that Darlene helped hold down Gibbs, reported the Associated Press. He also told the court that Delores stayed out of the room when the murder occurred, according to “Exhumed: Killer Revealed.”

The jury returned after deliberating about five hours. Darlene Phillips was convicted of conspiracy to commit first-degree murder and was sentenced to life. Delores Christenson was acquitted of all charges.

“I would imagine the jury looked at the fact that she did stay in the the kitchen during the murder,” said Penfield.

Delores didn’t receive any part of Gibbs’ estate because of her involvement in his murder.

To find out more about the case, watch “Exhumed: Killer Revealed,” airing Sundays at 7/6c on Oxygen, or stream episodes here.