Gruesome new details in a murder case set in the tiny southwest Colorado town of Parlin show a man was killed in his sleep and buried by members of his family in a pit with sheep heads — all done to settle a long-brewing feud over who should inherit a $3 million ranch.

Gunnison County District Court records say Deborah Sue Rudibaugh in July confessed that she killed her 29-year-old son and buried his 170-pound body by herself more than two years before. But investigators thought the confession by the 5-foot-tall, 70-pound woman was a ploy to spare her daughter and son-in-law from blame for the murder of Jacob Henry Millison.

Since then, state and local detectives have been piecing together a case. On March 1, Rudibaugh’s 33-year-old daughter, Stephanie Jackson, was arrested on a charge of first-degree murder. Rudibaugh, 68, was arrested the next day on the same charge. Jackson’s husband, David Jackson, 34, on Tuesday was taken into custody.

All three are being held in the Gunnison County jail, facing multiple felony charges related to Millison’s death, including tampering with a corpse.

According to arrest warrant affidavits, the family had been feuding over an inheritance from Rudibaugh’s second husband, Rudy. Before his death, Rudy gave sums ranging from $35,000 to $45,000 to his four children from his first marriage, and $30,000 to Stephanie to help her buy a home in Denver.

Rudy died in 2009, leaving the 700-acre 711 Ranch to Deborah in his will. In 2012, the Jacksons rented out their Denver home and returned to the ranch.

Court records show that conflict between the Jacksons and Millison was fierce. Millison took out a restraining order after David Jackson pulled a gun on him in January 2013, soon after which the Jacksons moved to Gunnison.

Millison vanished May 16, 2015, but all of his vehicles and his beloved dog, Elmo, were still at the ranch.

Despite the restraining order, the Jacksons moved back on the ranch. David Jackson was seen riding Millison’s prized vintage Harley Davidson motorcycle around town.

Friends started asking Rudibaugh where her son was. She told them he had gone to jiujitsu camp in Reno, Nevada; that he went with an unknown friend on a three-month camping trip; and that he went to visit his father in New Mexico.

Gunnison Sheriff’s Deputy Mark Mykol began an investigation after several people, including Mount Crested Butte police Officer Jared Hooks, filed missing-persons reports.

Mykol’s made numerous visits to Rudibaugh, starting on May 26, 2015. Over the next two years, she told him Millison was on a motorcycle trip to California or went to work at a martial arts dojo. She said her son used cocaine, steroids and mushrooms, and hung out with a dangerous crowd. She said he swiped books from her, including “How to Disappear Without Leaving a Trace.”

When police interviewed Rudibaugh in June, she told them when Millison “deserted” her after she tore up a will that divided the ranch between him and Stephanie and replaced it with one that named only her daughter as a beneficiary. The will leaving everything to Stephanie Jackson had been signed and witnessed in April 2015, before Millison’s death.

In July, Rudibaugh confessed to killing her son and showed deputies where she had buried him. She claimed she killed her son in self-defense after he threw her down in a ditch, climbed on her chest and choked her, threatening to kill her if she didn’t write a new will that excluded the Jacksons. He threatened her so much she began hiding guns under her mattress.

“Sibling rivalry had gone beyond everything,” she told investigators. “I was afraid he was going to kill me.”

Rudibaugh, who has breast cancer, said she sneaked into Millison’s bedroom early May 16, 2015, and shot him in the head with her Smith & Wesson .357 “Lady Smith” revolver. Over the next two days, Rudibaugh claimed she wrapped the body in plastic, rolled him in a carpet and shoved him down the stairs. She said she used “Yankee ingenuity” and a front-end loader to bury him in a pile of horse manure in a corral. She later moved the body because she was afraid that bears, raccoons or mountain lions would dig him up.

She said she planned to leave a letter explaining why she killed her son and a map showing where his body was for police upon her death, according to the affidavit.

Rudibaugh’s attempt to shield her daughter and son-in-law quickly began breaking apart.

Rudibaugh claimed the Jacksons were in Denver the day she shot her son, but cellphone records indicated they were in Gunnison, the affidavit says.

Stephanie’s cellphone records indicated that a message sent at 3:17 a.m. on May 16, 2015 — “It’s time to play!” — was deleted six minutes later. She later posted this Facebook message: “Have you ever been woken up with such awesome news you wanted to run outside screaming?”

When Stephanie and David took polygraph tests, the results indicated they lied about whether they caused or participated in Millison’s death. Both later admitted planning the murder and helping to move Millison’s body, but they said they didn’t participate in the shooting.

In another interview, Rudibaugh told police that her daughter told her once that the only way that Millison would leave the ranch was if he was taken out in a body bag. But Rudibaugh said shooting her son was her decision alone.

But investigators said, “Stephanie was the only person with a motive to kill Jacob.”

“Stephanie knew that Deborah’s will had been changed to make her the sole heir of the ranch,” the affidavit says. “Stephanie’s lies and actions after the murder show that she knew Jacob was dead immediately … and intended to cover up the homicide.”