BELLE FOURCHE, S.D. - Jurors convicted one woman of conspiracy to commit first-degree murder but acquitted her twin sister of charges that they helped to kill the 85-year-old man each had married twice.
Darlene Phillips was convicted of the most serious charge but cleared of all other charges. Her sister, Delores Christenson, was acquitted of all charges.
The jury returned after deliberating about five hours.
Phillips received mandatory life in prison.
When asked by the judge if she had anything to say before sentencing she quickly blurted out, "I'm not guilty, sir."
One of the twins was named beneficiary of the man's estate.
Phillips and Christenson, 46, each has been married four times. Both had brushes with the law before they were indicted in the death of Walter Gibbs, who was slain April Fools' Day 1990 at his home in Lemmon.
"Walter was a nice guy until he got mixed up with those nitwit twins," said Lillian Burns of Morristown, whose husband, George, was a close friend of Gibbs. "They're crazier than a couple of bedbugs."
Jerome D. Phillips, 38, a convicted rustler who's married to Darlene but says he's in love with her sister, confessed to smothering Gibbs with a pillow. He testified at the twins' trial this week that Darlene helped hold down Gibbs.
Phillips pleaded guilty May 21 to a murder conspiracy charge. He is to be sentenced July 2.
The twins are charged with planning the murder and helping to kill the frail Gibbs.
Phillips said he and the twins had several discussions about ways to kill Gibbs, who had named Christenson as heir to his $178,000 estate.
State Assistant Attorney General Mark Smith said in closing arguments yesterday that the sisters had persuaded Gibbs to change his will in January 1990.
Smith told the jury Darlene Phillips admitted to investigators that she helped smother Gibbs.
He said Christenson "sat in the kitchen while Jerome and Darlene went into the living room and did in Walter Gibbs."
Darlene Phillips' lawyer, Bruce Hubbard, said in his closing argument that the sisters were intimidated into helping kill Gibbs, and that Jerome Phillips was the mastermind of the plot.
He said Darlene Phillips obeyed her husband, who is 6-foot-1 and 280 pounds, because she was afraid he would harm her if she didn't.
Bob Van Norman, who represented Christenson, told the jury his client essentially has the mental capacity of a second-grader and is not nearly smart enough to either plan Gibbs' death or to know that she should report the murder scheme to authorities.
Gibbs was 58 when he first married Christenson, who was 18 at the time. They were divorced about 10 years later, and he married Darlene. Another divorce, two remarriages to the twins and one other marriage brought his total to five marriages.
"It's confusing to everybody who knows them," Burns said.
Darlene Phillips already is serving a 50-year prison term for trying to burn down Gibbs' farmhouse in 1989 while he was sleeping on the couch. A neighbor saw the fire and helped Gibbs get out.
Phillips was sentenced in August 1990, four months after Gibbs' death.
Authorities first thought Gibbs' death was natural but got suspicious several months later when they received a tip that Darlene Phillips was blabbing in prison about a murder.
Gibbs' body was exhumed 13 months after burial. Officials had thought he died at the hospital in Lemmon, a town of 1,600 in northwestern South Dakota just three blocks from the North Dakota line. Although his body was taken to the hospital, they didn't discover until later that he was dead when an ambulance picked him up.
Jerome Phillips is serving eight years for rustling sheep and pigs last year. Christenson served 60 days for helping him.
Darlene Phillips met her present husband in the state's prison for men and women several years ago when she was serving time for torching a house in Bison, and he was in jail for writing bad checks.
"The twins tell me I'm like a brother to them," said Lemmon Police Chief Nick Schaefer. "I don't know why because I've arrested them several times."
Friends of Gibbs said he was a sucker for a hard-luck story. That's why he remarried the twins and why after divorcing them he later let them and Jerome Phillips live with him, they said.
Neither twin testified at the trial, which was moved 120 miles to Belle Fourche because their attorneys said they couldn't find an impartial jury in Bison, population 300.