DENVER -- At first, Nancy Mason's parents thought their daughter’s death was an accident, that she fell off a cliff while fishing in Chaffee County five years ago.

A review of what happened, however, has led to suspicions of murder and arrest warrants, but the case has now stalled.

For the first time, William and Miriam Gaede are talking about the ordeal.

They believe she was murdered for her money, but proving it is another matter.

“Every day, once an hour, I think of the whole scenario and try to figure it out, and I just can’t think of a way to go any further,” said William Gaede, Nancy Mason’s father.

He and Nancy’s mother, Miriam Gaede, said the story of Nancy falling off a cliff while she was fishing never rang true.

“When you have bad feet, you don’t climb around on rocks, and besides, she was kind of heavy, and that’s just not something she was interested in,” said Miriam Gaede. “When we went on trips like that, she would stay in the cabin or in the car and read a book with a blanket wrapped around her.”

The fact that weeks before her death, Nancy Mason made her husband of six months, Dan Mason, the sole beneficiary of her insurance policy and will also seemed suspicious, the Gaedes said, especially since two of her son’s names were misspelled in the documents.

“Then we started piecing things together and could see that she wouldn’t do that. It was not an accident,” said William Gaede.

But the coroner at the time ruled that her death was an accident, and prosecutors said a lax investigation followed with no forensic autopsy, no recorded statements and no body. Dan Mason had his wife cremated.

“Nothing was done right,” said Miriam. “The Sheriff’s department has done everything they can to try to rectify that, but it’s very frustrating.”

Because of the evidentiary issues and in spite of a coroner’s inquest that ended with arrest warrants for Mason and his friend Efren Gallegos, District Attorney Thom LeDoux has decided not to file charges.

“It’s frustrating for us, too,” said LeDoux. “But my analysis is: Is there sufficient evidence to file criminal charges? Not just that something bad happened, but that a specific crime was committed by a specific individual -- we do not believe there is sufficient evidence.”

Nancy Mason’s parents haven’t given up their search for answers about what really happened to their daughter.

“It’s an injustice that one guy decided what 12 people ought to,” said William Gaede. “I’m not sure we’ll ever get justice.”

The Chaffee County attorney has filed a request seeking a special prosecutor for the case and to have the murder warrants reinstated.

The district attorney said if any new evidence comes to light, the case could be reopened.