EVERETT — A decade-old secret revealed could send an Arlington woman to prison for murder.

Detectives believe they have recovered the remains of the woman’s ex-husband, Byron Wright, secreted in a plastic bin under a concrete floor and two feet of dirt. Wright, 53, disappeared in the fall of 2004. His wife claimed that her husband suddenly skipped out on her with a twentysomething, well-to-do redhead. She said he took nothing, not even his beloved car collection.

It was the story, or versions of it, that she told the divorce court, Wright’s boss at Boeing and his sister.

Michele Donohue allegedly told a different story to her current husband and two buddies when she recruited them to move Wright’s body a few years ago, court papers said. Donohue allegedly admitted to them that she stabbed Wright. She reportedly said that Wright asked her to call an ambulance but she demanded an apology. The men say Donohue told them that Wright refused to apologize and she left him dying on the floor.

Donohue was arrested last week after detectives dug up the floor under an Arlington garage and discovered human remains. Donohue denied killing her husband and still maintained that Wright left her for another woman, court papers said.

Prosecutors on Wednesday charged Donohue, 48, with second-degree domestic violence murder. The charge was filed in district court. Prosecutors have until March 7 to refile the charge into Snohomish County Superior Court. The investigation is ongoing.

The medical examiner on Wednesday hadn’t released an identity or cause of death.

Detectives were unaware of Wright’s disappearance.

His sister told police she attempted to report Wright missing in 2009 but was turned away, court papers say.

Snohomish County sheriff’s detectives began investigating in December when a jailhouse informant stepped forward saying he knew about a killing and the victim’s whereabouts.

He said he’d heard the rumors from a man who claimed he helped cover up a murder.

The informant had been worried that Donohue might call the cops to rat out her new husband and others about the “chop shop” operating on the property. His buddy reassured him that Donohue would never call police. She had a big secret, the man said.

That’s when the man reportedly told the informant about the killing and how he helped move the remains from a shallow grave near the carport for reburial underneath a slab of concrete in the shop.

Detectives later wired the informant and sent him to the house with a copy of The Herald dated Jan. 23. The front page story was about Dennis “Slick” Lilly, a fugitive whose remains were recently found under a Gold Bar wood shed.

Detectives figured the newspaper story would help the informant bring up buried bodies without drawing too much suspicion. The ruse worked and the man allegedly is recorded on tape saying, “They ain’t gonna find nothing here. It’s under the concrete,” according to court papers.

Wright and Donohue were married in 2000. She filed for divorce in the months after Wright stopped showing up at Boeing, where he’d worked for 23 years. She told the court that she couldn’t serve Wright with divorce papers because she didn’t know where he was.

Donohue was awarded the house, a lot next to the house, eight vehicles, Wright’s Boeing stock and half of his pension. Donohue reportedly sold the lot for $110,000 and received about $125,000 from Wright’s pension.

Wright’s siblings told police that the Arlington man would have left his wife before he left behind his cars. Wright was an avid racing fan. He was a bit of a homebody, they said. He had grown up poor and was proud of his home and his car collection, the family told detectives.

Diana Hefley: 425-339-3463, hefley@heraldnet.com.