The thriller writer John Grisham is working on a screen-play about the murder and rape of an 18-year-old navy wife in the hope of securing pardons for four men he believes were wrongly convicted, even though they confessed repeatedly to the crime.

Michelle Moore-Bosko had eloped with her husband, Bill Bosko, just two months before her murder in 1997. They had set up home in a modest flat near his naval base in Norfolk, Virginia, and were planning a second, “big wedding”, which their parents could attend.

Bosko returned from a week at sea to find the house was “nice and clean” until he walked into the bedroom. “I found my wife butchered on the floor,” he said.

He ran to a neighbour, Danial Williams, a fellow member of the navy, crying out, “My wife is dead”. Williams, 35, is serving a life sentence for her murder after a friend claimed he was “obsessed with Michelle”. Another six men went on to be accused of raping and killing Moore-Bosko.

Four men, all belonging to the navy, were jailed, although one who was convicted only of rape was released after serving eight years. Charges against three other men were dropped.

No DNA evidence linked any of the convicted men to the crime. In 1999 an eighth suspect emerged from the shadows: Omar Abdul Ballard, who was sentenced to 40 years’ imprisonment for attacking and raping a woman 10 days after Moore-Bosko was killed, only a mile from her flat. He was not linked by police to her murder but wrote a letter in jail, claiming, “Michelle got killed, guess who did that, Ha Ha Ha.”

Ballard’s semen and blood matched DNA found at the scene. He told police that he had worked alone, a claim supported by the even stab wounds on her body, and said, “Them four people that opened their mouths is stupid.” Yet he, too, later claimed they had participated in the murder, a statement he now says was “totally false”.

For Grisham, who has sold 250m copies of thrillers including The Pelican Brief and The Firm, which were turned into Hollywood films, the case of the “Norfolk Four” sheds light on the “unbelievable world of false confession”.

The parents of Moore-Bosko, in contrast, are convinced of the men’s guilt. In a statement, they said they were “devastated to learn that . . . people with inaccurate information and personal agendas are attempting to profit from the tragic death of our daughter. Please do not put us through this again”.

The Norfolk Four are hoping to be pardoned by Tim Kaine, the governor of Virginia, but he has said it could be difficult to disregard as many as 12 taped confessions. One of the convicted men described calmly on tape how seven men took turns raping Moore-Bosko, urging him to “just go ahead and stab the bitch”.

The foreman of the jury said: “Nothing could blunt the force of that taped confession.”

However, no tape exists of the men’s interrogations. What began as a simple murder accusation against one man, Williams, turned into an ever-growing list of participants when police grew frustrated by the lack of a DNA match. The case is unusual because the absence of DNA evidence served to ensnare rather than exonerate the men.

Williams, the first suspect, initially denied killing Moore-Bosko but claims he was bullied into confessing after the detective in charge of the case threatened him with the death penalty. “They wear you down to the point that you are exhausted,” he said. “I just wanted the questioning to end.”

Six months later, the police went on to arrest his flatmate Joe Dick, then 21, who has wit-nesses to support his claim that he was on board a naval ship at the time. Yet he not only confessed to the crime, but testified in court against two of his codefendants. Before he was sentenced, he apologised to Moore-Bosko’s parents.

“I know I shouldn’t have done it,” he said. “I have got no idea what went through my mind that night and my soul.”

A naval officer described Dick as mentally impaired: “The Joseph Dick I knew couldn’t chew bubblegum and tie his shoes at the same time.”

Dick told The New York Times his mind had been “messed up” by detectives. “It didn’t cross my mind that I was lying. I believed what I said was true,” he said.

By the time Ballard emerged as the killer, none of the men’s stories matched. Instead of reexamining their cases, the police surmised that Ballard must have been present with them, even though he was a complete stranger. By then, the “neat and clean” apartment, described by Bosko, had become the alleged scene of a gang rape and murder by up to eight rampaging men.

Ballard now claims he changed his story to fit the police’s account in exchange for the offer of a life sentence rather than the death penalty.

Yet the notion that so many members of the navy could be pressured into false confessions defies belief, says a former prosecutor of the case. He believes the men’s protestations of innocence are “soundbites” invented by the “clemency gang”.

Grisham thinks that freeing the men could be an uphill struggle. “I don’t know if they can be helped,” he said. “They have many years to go in prison.”

Times Recommends

• Should Knox’s trial even have reached the courtroom?
• 'Was it real?' The US bailout nightmare
• Iranian opposition plays the long game