CHADWICK, Mo. -- -

Two national cold cases spanning more than 30 years have come to life in the Ozarks and focused on an elderly couple.

Gerald Uden, 71, and Alice Louise Uden, 74, were quietly living out their senior years in the rural Ozarks near Chadwick.  The couple attended church and raised two adult children in the small town.

"They were good people; we've known them for about 12 years now. They're the kind of neighbors you leaned over the fence and talked about your chickens with," said Allen Bishop. "They were just the old neighbors next door."

Now they face extradition to Wyoming -- to answer murder allegations tht authorities say have gone unpunished for more than 33 years.

"Just disbelief.  They are old people, they don't do things like that," said Bishop.  "They just seemed like super nice people.  This was absolute shock."

Bishop said Gerald Uden worked as a long-haul trucker.  Initially, his wife, Alice, would go with him, however recent health problems have forced her to stay home.

"She had a lot of health issues.  She has cancer and she's plagued with diabetes, and she had a lot of other things, thyroid problems," said Bishop.  "We would just kind of check in on her and make sure that she was okay."

Alice Uden is accused of killing her ex-husband, Ronald Holtz, 25, who disappeared in 1974 or 1975.

As long ago as 1989, somebody told police that Alice Uden had confessed in 1975 or 1976 to shooting Holtz in the back of the head while he slept, according to an affidavit.

The affidavit did not identify the witness.  Alice Uden allegedly told that person she'd wrapped Holtz's body in some blankets and placed his body in a cardboard barrel.

Alice Uden allegedly told the witness she'd then dumped the barrel in an abandoned gold mine on a ranch where she'd been living as a caretaker in the mid-1970s.

Relatives of Holtz told investigators they hadn't seen or heard from Ronald Holtz since Christmas of 1974. U.S. Department of Veterans Affairs records show Holtz was released from a VA hospital in Sheridan on Dec. 24, 1974, according to the affidavit.

Alice Uden and Ronald Holtz married on Sept. 17, 1974.  Alice Uden filed for divorce on Feb. 5, 1975, and the divorce was granted because Holtz was never located to be served with divorce papers, according to the affidavit.

In 2007, the witness allegedly showed investigators where to find the mine where Alice Uden said she'd dumped Holtz's body.  An excavation this August uncovered human remains 40 feet down the mineshaft and DNA testing showed they were Holtz's, the affidavit states. 

Holtz had been shot in the head. 

Holtz's remains recently were found in an abandoned mine in Laramie County in southeast Wyoming.

"She had been a suspect in her husband Holtz's disappearance basically since it began, but they didn't have any evidence to detain or arrest her on," said Christian County Sheriff Joey Kyle.  "You go years knowing who did it, but just being able to prove it and then something will turn up, some small piece of information that will allow you to completely unmask the crime and all of a sudden it will turn into an arrest and potential conviction."

Wyoming investigators asked for help from the Christian County Sheriff's Office.  Initially, Kyle said, a Missouri prosecutor didn't want to sign an arrest warrant.

"The prosecutor thought the case was -- how can I put it -- stale," said Kyle. "But we convinced them to take Alice into custody and see what she knew."

Kyle said the woman corroborated the information investigators had about her case.  She was arrested Thursday and charged with one count of first-degree murder.

Investigators also wanted to bring in her husband, Gerald for the disappearance of his ex-wife.

Virginia Uden, 32, and her two children, Richard Uden, 12, and Reagan Uden, 10, were last seen in central Wyoming in 1980.

According to an affidavit, Gerald Uden confessed to an investigator at his home Friday that he'd shot Virginia Uden and her two children with a .22-caliber rifle that Virginia Uden had brought so they could all go bird hunting.

Uden allegedly said he'd picked up the three on Sept. 13, 1980, and drove them to an area near Pavillion in Fremont County. All four got out of the car and Uden shot his ex-wife, then both boys, according to the affidavit.

He then allegedly proceeded to conceal the bodies.

Deputy Fremont County Attorney Patrick J. LeBrun declined to comment on any details of the case, including whether the bodies of Virginia Uden and her two children were ever found.

The cases are likely to stir up old sentiments out in Wyoming's open spaces.  Earlier this year, the mother and grandmother of the Fremont County victims died without seeing any resolution in that case.

"Mrs. Martin spent the remainder of her life with the hope of learning what happened to them," read the April 11 obituary in The Riverton Ranger for Claire "Peg" C. Martin, 92.

"The families of these folks who are deceased, they are going to get some closure and there's some gratification there," said Kyle.

What role their own relationship may have played in the slayings remains murky. Court documents have yet to hint at motives or indicate at what point Alice and Gerald caught each other's eye and authorities are tight-lipped about details of their investigations.

Neighbors said they are still processing the information about the people they thought they knew.

"I can't judge them too harshly, I hope someone can prove their innocence, but at the same time, justice needs to be done. Whatever it is," said Bishop. "There's something to be said for the life that they've lived for the past 40 years."

The Associated Press' Jim Salter and Alan Scher Zagier in St. Louis, Mo., and Bob Moen in Cheyenne contributed to this report.