St. Joseph, Mo. ? A man and his mother have admitted guilt to charges in the death 24 years ago of his former wife, a crime that went unsolved until a tip led to discovery of the body in May.

Appearing Thursday in Buchanan County Circuit Court, Shirley Milbourn, 67, said she shot Rhonda Burgess during an argument in November 1981, and her son, Michael Milbourn Sr., 44, said he mopped up the blood and hid the body.

Shirley Milbourn pleaded guilty to second-degree murder. A second-degree murder charge against her son was dropped in return for his guilty plea to abandoning a corpse and tampering with physical evidence. Prosecutors also agreed not to file additional charges against either of them.

Milbourn and Burgess, who was 22 when she disappeared, married in 1979. She gave birth to a son, Michael Jr., the following year, and they were divorced in January 1981.

Shirley Milbourn testified Thursday that Burgess came to her St. Joseph home to visit the child on Nov. 28, 1981, and began yelling and threatening to take the boy.

She said she went upstairs to get Michael Jr., while her son and his former wife continued arguing in the kitchen.

Burgess, she said, began hitting her son, and he yelled for help.

“I went in the bedroom and got a shotgun and brought it down the stairs,” she said. “She was still talking and I shot her.”

Shirley Milbourn, who said Burgess had a knife, said she shot her two times. She said she and her son took the body to family-owned farmland in neighboring Andrew County and buried it.

“I went to get the body, cleaned up at the house,” her son testified. “Cleaned the blood up and hid the body.”

Michael Milbourn pleaded guilty to the two lesser charges although the statute of limitations on them had expired. Dwight Scroggins, the county prosecutor, said those charges reflected what the evidence supported.

Milbourn’s attorney, Tim Warren, agreed, saying his client “was in fact guilty of the two offenses he pled to.”

“He was not guilty of murder,” Warren said. “I think it gave closure to the case. I think it gave Mike the chance to do the right thing.”

“There isn’t anything about this that is satisfying but I do think it’s an appropriate conclusion to a very unusual set of circumstances,” Scroggins said.

Members of the Milbourn family and attorneys for Shirley Milbourn declined comment. Kenny Burgess, brother of the slain woman, said members of her family agreed with the plea bargain.

“It was time to get this thing put behind us,” Burgess said.

“They probably could have done a better investigation if you ask me, but I’m glad it’s done and over and that justice was served,” said another brother, Paul Burgess. “My sister sat out there 23 years in a grave and rotted. I don’t think that was fair at all.”

Police had closed their investigation into Rhonda Burgess’ disappearance in 1982. The case was re-opened in May after a tip from a granddaughter of Shirley Milbourn, and human remains were discovered on the Andrew County farm. They were identified through DNA as those of the missing woman.

The Milbourns will be sentenced Jan. 27 by Judge Dan Kellogg. Shirley Milbourn faces 10 years to life, her son up to eight years and a $10,000 fine. As part of the agreement, prosecutors are recommending a 30-year cap on Shirley Milbourn’s sentence and eight years for her son, with credit to him for the time spent in the county jail.