A mysterious note, now missing, left on the homicide victim's grave.

A pair of brothers charged in their sister's slaying before one agrees to testify against the other, after a dozen years of closely guarded family silence.

A witness contacting a grand jury member on the sly.

The 15-year-old case of Leisa Martin's death has all the truth-defies-fiction elements of a movie thriller.

But for Troy Martin, of Bagley, Minn., in Clearwater County District Court for a second time to face murder charges in his sister's death, the harsh reality of a possible 40-year prison term looms.

In a rare decision, the Minnesota Court of Appeals last December invalidated a grand jury's second-degree murder indictment of Martin, finding that jurors wouldn't have reached that decision if not for improperly admitted evidence and misconduct by prosecutors — including a witness's improper contact with a juror and participation in deliberations by the county's attorneys — during the jury's two weeks of proceedings.

Now, Martin again faces second-degree murder charges in his sister's death, this time by way of a criminal complaint based primarily on testimony from his brother Todd.

"I've never seen such a fiasco," said John Undem, Troy Martin's attorney. "I know I'm the defense attorney, but I've never seen an innocent man pursued so relentlessly. It's the worst miscarriage of justice I have ever seen."

But Richard Mollin, who took over as Clearwater County attorney in 2011 and was not part of the original prosecution that resulted in the nullified indictment, said the facts in the case still support the renewed charges.

"The basis of the Court of Appeals ruling was errors in the manner in which the indictment from the grand jury was obtained, not the substance of the case that brought it to the grand jury in the first place," Mollin said.

The appeals court's ruling doesn't preclude filing a complaint on second-degree murder charges if a grand jury's indictment is thrown out. The decision will have no bearing on the new effort to prosecute Martin, Mollin said.

Undem last week argued for dismissal of the charges before District Judge Paul Benshoof. Mollin will have a chance to argue in response next month, and the judge will make a ruling soon after. If Benshoof decides to proceed with a jury trial, it is scheduled for early next year.

Leisa Martin's death

Both Martin brothers have remained free as the case progresses in Bagley, a northwestern Minnesota community of 1,400 where homicides are almost unheard of.

Leisa Martin, 31, died from asphyxiation due to an assault in the early hours of Oct. 28, 1998, at her mother's Bagley home, where the family was living, according to the medical examiner's report.

According to the new complaint, Todd and Leisa Martin were dropped off at the home after an evening of drinking in nearby Clearbrook. As the pair continued to drink on the porch, Leisa started talking about her ex-husband.

"I kind of told her I didn't want to hear it," Todd Martin told investigators.

Leisa Martin threw a can of beer at her brother as the argument escalated, and Troy Martin came from the house to calm them down, the complaint says, then held down his sister.

She had "snaked out" in similar fashion before, Todd Martin would testify, and restraining her — sometimes to the point where she briefly couldn't breathe — was the only way to settle her down.

The brothers thought she had merely passed out from drinking, but after about 20 minutes, they found her unresponsive, the complaint said.

They never tried CPR nor did they call 911 or their father, who was a physician.

Todd Martin said they put her body in a car and brought it to an isolated stretch of woods along Roy Lake in Mahnomen County, where they buried it in a shallow grave.

Three days later, the body was found by two men looking for firewood.

At the time, both brothers denied involvement in their sister's death.

Over the next 11 years, investigators chased nearly 1,000 leads trying to unravel the mystery of her death. Court documents say the investigation pointed to a family member "and Todd Martin in particular, but was stymied by a lack of physical evidence."

'I'm totally lost'

Court documents refer to the family's "shroud of silence" following Leisa Martin's death. And Steve Hagenah, who was part of nearly every homicide investigation in northern Minnesota before retiring after 29 years as an agent with the state Bureau of Criminal Apprehension, found the lack of concern both troubling and unusual.

"I don't think I've ever in my career worked a case where I wasn't getting phone calls from family members routinely asking me what the status, what the progress of the case was, what was going on, do we have any leads," Hagenah said.

Investigators finally got their break when, after he was arrested on a drunken-driving charge in 2010, Todd Martin implicated his brother.

Both brothers initially faced charges of aiding and abetting second-degree manslaughter, aiding an offender, and aiding and abetting interference with a dead body.

However, Todd Martin struck a deal with prosecutors to testify against his brother in exchange for the most serious charges against him being dismissed.

Arguing that there was no probable cause to charge Troy Martin, who passed a polygraph test and who claims he was asleep in the house when his sister was killed, Undem pointed to the inexplicable loss of two key pieces of evidence that could help his client's cause.

During Todd Martin's DWI arrest, he attacked and strangled the deputy and made statements about his sister's death. "Conveniently, they have lost that tape recording" of the deputy's call for assistance, Undem said.

Todd Martin was allowed to plead down on those charges after implicating his brother in the killing, he added.

Second, a note scrawled on a bank deposit slip bearing the name of a witness suspected in helping move Leisa Martin's body was found on her grave in 2003 by three of her friends.

Part of the note addressed to her read: "My life is really funny now. Words cannot explain what I feel. I'm totally lost."

But that note, which may have offered DNA or handwriting evidence, was lost by investigators, Undem said.

Mollin said that's just part of the challenge of prosecuting a 15-year-old case. He said the issues remain unchanged from what led the first grand jury to its conclusion.

"Those people heard a full two weeks of testimony from 18 to 19 people" that led to Troy Martin's indictment, he said. "We came to the conclusion that those errors did not preclude us from proceeding."

Jim Anderson • 651-925-5039 Twitter: StribJAnderson